This session aims to place recently observed climate change in a long-term perspective by highlighting the importance of paleoclimate research spanning the past 2000 years. We invite presentations that provide insights into past climate variability, over decadal to millennial timescales, from different paleoclimate archives (ice cores, marine sediments, terrestrial records, historical archives and more). In particular, we are focussing on quantitative temperature and hydroclimate reconstructions, and reconstructions of large-scale modes of climate variability from local to global scales. This session also encourages presentations on the attribution of past climate variability to external drivers or internal climate processes, data syntheses, model-data comparison exercises, proxy system modelling, and novel approaches to producing multi-proxy climate field reconstructions.

Modelling past climate states, and the transient evolution of Earth’s climate remains challenging. Time periods such as the Paleocene, Eocene, Pliocene, the Last Interglacial, the Last Glacial Maximum or the mid-Holocene span across a vast range of climate conditions. At times, these lie far outside the bounds of the historical period that most models are designed and tuned to reproduce. However, our ability to predict future climate conditions and potential pathways to them is dependent on our models' abilities to reproduce just such phenomena. Thus, our climatic and environmental history is ideally suited to thoroughly test and evaluate models against data, so they may be better able to simulate the present and make future climate projections.

We invite papers on palaeoclimate-specific model development, model simulations and model-data comparison studies. Simulations may be targeted to address specific questions or follow specified protocols (as in the Paleoclimate Modelling Intercomparison Project – PMIP or the Deep Time Model Intercomparison Project – DeepMIP). They may include anything between time-slice equilibrium experiments to long transient climate simulations (e.g. transient simulations covering the entire glacial cycle as per the goal of the PalMod project) with timescales of processes ranging from synoptic scales to glacial cycles and beyond. Comparisons may include past, historical as well as future simulations and focus on comparisons of mean states, gradients, circulation or modes of variability using reconstructions of temperature, precipitation, vegetation or tracer species (e.g. δ18O, δD or Pa/Th).

Evaluations of results from the latest phase of PMIP4-CMIP6 are particularly encouraged. However, we also solicit comparisons of different models (comprehensive GCMs, isotope-enabled models, EMICs and/or conceptual models) between different periods, or between models and data, including an analysis of the underlying mechanisms as well as contributions introducing novel model or experimental setups.

Extreme events and natural hazards are frequent occurrences on our unstable planet. They are predicted to become more common, severe and costly in the future and this session explores their role in human prehistory and history. In order to understand the potential of contemporary and future extreme events to impact human societies, it is critical to understand the mechanisms of how they may have occurred in the past, and elucidate their effects. This session invites contributions from across relevant disciplines. Global in scope and not limited to specific types of extreme events or natural hazards, we hope to compare and contrast differing methods and datasets that address the character and role of extreme events in the human past. Ultimately, we also seek to discuss how the evidence base of Pleistocene and Holocene calamities can be brought into play in the discussion about sustainability and disaster risk reduction in the Anthropocene, as well as to explore how extreme events may have shaped our past.

This session will focus on the emerging discipline of Conservation Paleobiology that uses the data from the fossil record and sedimentary archives to inform biodiversity conservation and ecosystem management. Even though humans have altered ecosystems for millennia, direct ecological observations rarely encompass more than the last few decades. At the same time, the accelerating pace of global climate change requires better understanding of the long-term resilience and adaptive capacities of ecosystems facing multiple stressors. The youngest fossil record can offer high-resolution insights into ecosystem change on timescales well beyond the limits of ecological monitoring, enabling the reconstruction of ecological baselines and natural range of variability. Additionally, the pre-Quaternary geologic record provides a series of natural experiments allowing assessment of biotic responses to major environmental perturbations, strengthening the theoretical foundations of conservation science.

We invite presentations offering both the near-time and deep-time perspective on ecological and evolutionary processes operating during times of rapid environmental changes, ranging from the Anthropocene biodiversity crisis to Phanerozoic mass extinction events. We also welcome contributions highlighting potential biases affecting the fossil record by linking stratigraphic, taphonomic and ecological patterns. We hope to stimulate discussion on novel opportunities and limitations of using different types of geohistorical data to address some of the most urgent questions in Conservation Biology.

The consequences and impact of climate change for ecosystems, landscapes and human societies depend on the rate, duration and nature of change. While paleoclimate archives provide ample records of such climatic variability, a lack of proxy sensitivity, in combination with chronological uncertainties in age models, often make it difficult to identify the actual agents of change for a specific region. A key example is the Younger Dryas (YD), which is expressed in Western Europe as a significant cold period, but also drying, which possibly lagged the cooling by a century or so. Contrary, in Eastern Europe, paleodata suggest that cooling was restricted to winter season, only, whereas summer temperatures were mostly stable. The resulting massive ecosystem change during the YD has been attributed variably to cooling as well as drying and/or possible changes in seasonality.

With significant advances in relative and absolute chronological techniques (e.g., tephrochronology and cosmogenic radionuclide synchronization) which enable the comparison of ecosystem responses on common timescales, as well as an increased proxy understanding and modelling, it is now becoming possible to disentangle the different components of the climate system and compare their responses over continental scales.

Focussing on the last glacial-interglacial cycle we invite contributions that assess, diagnose, model and quantify the agents of climatic change, as well as those that permit new insights into the rates during abrupt transitions. We particularly welcome research (including modelling studies) that address the importance of temperature, hydrological and seasonal changes using archives (e.g., ice core, marine and terrestrial), and those that advance our understanding of the responses of different paleoclimate proxies. A better understanding of both the cause AND effect of past abrupt climate changes and spatio-temporal differences is needed for a better prediction of the consequences of the anthropogenic interference with the climate system.

The half-century since the first deep ice core drilling at Camp Century, Greenland, has seen extensive innovation in methods of ice sample extraction, analysis and interpretation. Ice core sciences include isotopic diffusion analysis, multiple-isotope systematics, trace gases and their isotopic compositions, ice structure and physical properties, high-resolution analysis of major and trace impurities, and studies of DNA in ice, among many others. Several projects (e.g. Beyond EPICA Oldest Ice) are to surface ice as old as 1.5 million years old from very compressed layers at the very bottom of the Antarctic ice sheet in the coming years. Analysis and interpretation of this ice will bring new challenges, including the potential for in situ processes to impact the climatic signals. Furthermore, a variety of ice cores have been drilled recently in the framework of the ICE MEMORY initiative to preserve environmental and climate information from glaciers threatened by climate change.
This session welcomes all contributions reporting the state-of-the-art in ice coring sciences, including drilling and processing, dating, analytical techniques, results and interpretations of ice core records from polar ice sheets and mid- and low-latitude glaciers, remote and autonomous methods of surveying ice stratigraphy, and related modelling research.

The pacing of the global climate system by orbital variations is clearly demonstrated in the timing of e.g. glacial-interglacial cycles. The mechanisms that translate this forcing into geoarchives and climate changes continue to be debated. We invite submissions that explore the climate system response to orbital forcing, and that test the stability of these relationships under different climate regimes or across evolving climate states (e.g. mid Pleistocene transition, Pliocene-Pleistocene transition, Miocene vs Pliocene, and also older climate transitions). Submissions exploring proxy data and/or modelling work are welcomed, as this session aims to bring together proxy-based, theoretical and/or modelling studies focused on global and regional climate responses to astronomical forcing at different time scales in the Phanerozoic.

Over the last 1.5 Myr the rhythm of glaciations changed from a 40 kyr world to a 100 kyr world, known as the Mid-Pleistocene Transition (MPT). This transition does not follow directly from Milankovitch theory. Against the background of the start of a new deep drilling project in Antarctica (Beyond-Epica) covering this period in a few years from now, we encourage the broader paleo community to show their latest results on the mechanisms underlying the transition. We invite presentations on changes in proxies over this time as well as model studies providing insight in the processes and drivers of the Earth climate system over the MPT.

Polar regions are particularly sensitive to climate variability and play a key role in global climate and environmental conditions through various feedback mechanisms. In this session we invite contributions dealing with all aspects of Phanerozoic (i.e. Cambrian to Holocene) geology from high latitude regions: stratigraphy, paleoenvironment, paleoclimate, and modelling.

Mountain and ice sheet glaciations provide an invaluable record for past and present climate change. However, varying geomorphological process-systems, specific glaciological conditions and topography can make regional, intra-hemispheric and global correlations challenging. This problem is further enhanced by ongoing specialisation within the scientific community. Despite such challenges glacier and ice sheet reconstructions remains a crucial palaeo-enviormental proxy.

The primary aim of this session is to evaluate the potential of mountain and ice sheets glaciation records and stimulate further research in this important field of research. Contributions on all relevant aspects are welcomed, for example: (a) glacial landforms and reconstruction of past glaciers/ice sheets, (b) dating techniques and geochronology compilations, (c) glacier dynamics and palaeoclimatic interpretations, or (d) impacts of ecosystems and human evolution/society.

We would in particular like to invite contributions highlighting the specific conditions of mountain glaciations/ice sheet or addressing the relationship and connections between different of their aspects. To address the diversity of glaciations, contributions from high-, middle-, and low-latitude mountain ranges as well as from continental to maritime regions are all welcomed. The time scale of the session will range from Early Pleistocene glaciations to the LGM and Holocene/modern glaciers.

This session has steadily become more popular and attracted contributions from a wide range of research topics and study areas, both with a high diversity of methodological approaches. It has become a platform for everyone interested in the emerging collaborative research network “The Legacy of Mountain Glaciations” and given an opportunity to meet and exchange ideas and expertise.

The geological record provides insight into how climate processes may operate and evolve in a high CO2 environment and the nature of the climate system during a turnover from icehouse to greenhouse state — a transition that may potentially occur in the near future. In recent years we have seen major advances in many geochemical techniques and an increase in the complexity of Earth System Models. The aim of this session is to share progress in our understanding of global changes occurring during the pre-Quaternary based on the integration of geochemical/paleobotanical/sedimentological techniques and numerical models. Specifically, we encourage submissions describing research in which both model and data approaches are embedded. We invite abstracts that reconstruct Earth’s climate from the Cambrian to the Pliocene, investigate how the interconnections of the key surface reservoirs (vegetation-ocean-atmosphere-cryosphere-biogeochemistry) impact climate, and identify tipping points and thresholds. Pertinent themes may include greenhouse-icehouse transitions and intervals testifying for extreme changes.

The study of deep-time (pre-Quatrenary) climate evolution is important not only for understanding Earth’s habitable history but also for providing insights to present and future changes of the Earth system. To investigate deep-time climate, several international modelling intercomparsion projects, for example DeepMIP, MioMIP, PlioMIP, have been initiated. All these MIPs pay attention to the Cenozoic climate. However, relatively fewer modelling studies simulate climate in deeper time before the Cenozoic. This session invites works on deep-time climate simulations and reconstructions over the tectonic time scales, including, but not limited to, idealized and comprehensive model simulations, geological, geochemical, and paleontological reconstructions. We wish this session could integrate our knowledge of deep-time climate and environment evolution in the spirit of an integrated Earth system.

Processes responsible for formation and development of the early Earth (> 2500Ma) are not well understood and strongly debated, reflecting in part the poorly preserved, altered, and incomplete nature of the geological record from this time.
In this session we encourage the presentation of new approaches and models for the development of Earth's early crust and mantle and their methods of interaction. We encourage contributions from the study of the preserved rock archive as well as geodynamic models of crustal and mantle dynamics so as to better understand the genesis and evolution of continental crust and the stabilization of cratons.
We invite abstracts from a large range of disciplines including geodynamics, geology, geochemistry, and petrology but also studies of early atmosphere, biosphere and early life relevant to this period of Earth history.

During the past decades numerous sediment records have become available from lakes and paleolakes through shallow and (ICDP) deep drilling. These records have proven to be valuable archives of past climate and environmental change, human activities as well as tectonic and volcanic activity. We invite contributions emphasizing quantitative and spatial assessments of rates of change, causes and consequences of long- and short-term climate variability, impact, magnitude, and frequency of tectonic and volcanic activity as deduced from sedimentological, geochemical, biological, and chronological tools.

Tree rings are one of nature’s most versatile archives, providing insight into past environmental conditions at annual and intra-annual resolution and from local to global scales. Besides being valued proxies for historical climate, tree rings are also important indicators of plant physiological responses to changing environments and of long-term ecological processes. In this broad context we welcome contributions using one or more of the following approaches to either study the impact of environmental change on the growth and physiology of trees and forest ecosystems, or to assess and reconstruct past environmental change: (i) dendrochronological methods including studies based on tree-ring width, MXD or Blue Intensity, (ii) stable isotopes in tree rings and related plant compounds, (iii) dendrochemistry, (iv) quantitative wood anatomy, (v) ecophysiological data analyses, and (vi) mechanistic modelling, all across temporal and spatial scales.

Speleothems and continental carbonates (e.g. travertines, pedogenic, lacustrine, subglacial and cryogenic carbonates) are important terrestrial archives, which can provide precisely dated, high-resolution records of past environmental and climate changes. The field of carbonate-based paleoclimatology has seen (1) continuously improving analytical capacity, producing detailed records of climate variability integrating established as well as novel and innovative techniques. (2) Long-term monitoring campaigns facilitating the interpretation of high-resolution proxy time series from carbonate archives. (3) At the same time proxy-system models can help understanding the measured proxies, by describing processes such as water infiltration, CO2 and carbonate dissolution, and carbonate precipitation and diagenesis. Applied together, advancements in these cornerstones of carbonate related research pave the way towards developing highly reliable quantitative terrestrial climate reconstructions.
Here, we invite contributions that show progress in one of the three outlined domains. We especially welcome integrated and interdisciplinary studies, connecting these branches of carbonate related research in order to better understand the climate system on various time scales.

Carbonate (bio)minerals have played an essential role in the history of life on Earth, forming one of the most important archives for past climate and environmental change. Geochemical investigations have been crucial for understanding the evolution of microbial habitats and the paleobiology of carbonate biomineralizers since the Precambrian. With this session, we encourage contributions from sedimentology, geochemistry and biology that utilize carbonate (bio)minerals (e.g., microbialites, mollusk shells, and foraminifera) with the aim to reconstruct past environments, seasonality, seawater chemistry, and paleobiology in a wide range of modern to deep time settings, including critical intervals of environmental and climatic change. This includes theoretical or experimental studies of trace element partitioning and isotope fractionation and studies into original skeletal carbonate preservation and diagenetic alteration.

Climate services challenge the traditional interface between users and providers of climate information as it requires the establishment of a dialogue between subjects, who often have limited knowledge of each-other’s activities and practices. Increasing the understanding and usability of climate information for societal use has become a major challenge where economic growth, and social development crucially depends on adaptation to climate variability and change.

To this regard, climate services do not only create user-relevant climate information, but also stimulate the need to quantify vulnerabilities and come up with appropriate adaptation solutions that can be applied in practice.

The operational generation, management and delivery of climate services poses a number of new challenges to the traditional way of accessing and distributing climate data. With a growing private sector playing the role of service provider is important to understand what are the roles and the responsibilities of the publicly funded provision of climate data and information and services.

This session aims to gather best practices and lessons learnt, for how climate services can successfully facilitate adaptation to climate variability and change by providing climate information that is tailored to the real user need.
Contributions are strongly encouraged from international efforts (GFCS, CSP, ClimatEurope…); European Initiatives (H2020, ERA4CS, C3S, JPI-Climate…) as well as national, regional and local experiences.

As the most evident example of land use and land cover change, urban areas play a fundamental role in local to large-scale planetary processes, via modification of heat, moisture, and chemical budgets. With rapid urbanization ramping up globally it is essential to recognize the consequences of landscape conversion to the built environment. Given the capability of cities to serve as first responders to global change, considerable efforts are currently being dedicated across many cities to monitor and understand urban atmospheric dynamics and examine various adaptation and mitigation strategies aimed to offset impacts of rapidly expanding urban environments and influences of large-scale greenhouse gas emissions.

This session solicits submissions from both the observational and modelling communities examining urban atmospheric and landscape dynamics, processes and impacts owing to urban induced climate change, the efficacy of various strategies to reduce such impacts, and techniques highlighting how cities are already using novel science data and products that facilitate planning and policies on urban adaptation to and mitigation of the effects of climate change. Emerging topics including, but not limited to, compounding impacts with urban COVID-19 outbreaks or urban climate informatics, are highly encouraged.

Large-scale atmospheric circulation dynamics are the major driver of near surface climatic and environmental variability. Synoptic climatology examines atmospheric circulation dynamics and their relationship with near surface environmental variables. Within synoptic climatological analyses, a wide variety of methods is utilized to characterize atmospheric circulation (e.g., circulation and weather type classification, regime analysis, teleconnection indices). Various linear and non-linear approaches (e.g., multiple regression, canonical correlation, neural networks) are applied to relate the circulation dynamics to diverse climatic and environmental elements (e.g., air temperature, air pollution, floods).

The session welcomes contributions from the whole field of synoptic climatology. This includes application studies for varying regions, time periods (past, present, future) and target variables and in particular contributions on the development and the comparison of methods (e.g., varying circulation type classifications) and conceptual approaches (e.g., circulation types versus circulation regimes).

High-impact climate and weather events typically result from the interaction of multiple hazards across various spatial and temporal scales. These events, also known as Compound Events, often cause more severe socio-economic impacts than single-hazard events, rendering traditional univariate extreme event analyses and risk assessment techniques insufficient. It is therefore crucial to develop new methodologies that account for the possible interaction of multiple physical drivers when analysing high-impact events. Such an endeavour requires (i) a deeper understanding of the interplay of mechanisms causing Compound Events and (ii) an evaluation of the performance of climate/weather, statistical and impact models in representing Compound Events.

The European COST Action DAMOCLES coordinates these efforts by building a research network consisting of climate scientists, impact modellers, statisticians, and stakeholders. This session creates a platform for this network and acts as an introduction of the work related to DAMOCLES to the research community.

We invite papers studying all aspects of Compound Events, which might relate to (but are not limited to) the following topics:

Synthesis and Analysis: What are common features for different classes of Compound Events? Which climate variables need to be assessed jointly in order to address related impacts? How much is currently known about the dependence between these variables?
Stakeholders and science-user interface: Which events are most relevant for stakeholders? What are novel approaches to ensure continuous stakeholder engagement?
Impacts: What are the currently available sources of impact data? How can they be used to link observed impacts to climate and weather events?
Statistical approaches, model development and evaluation: What are possible novel statistical models that could be applied in the assessment of Compound Events?
Realistic model simulations of events: What are the physical mechanisms behind different types of Compound Events? What type of interactions result in the joint impact of the hazards that are involved in the event? How do these interactions influence risk assessment analyses?

Predictions of climate from seasonal to decadal time scales and their applications will be discussed in this session. With a time horizon from a few months up to thirty years, such predictions are of major importance to society, and improving them presents an interesting scientific challenge. This session aims to embrace advances in our understanding of the origins of seasonal to decadal predictability, as well as in improving the respective forecast skill and making the most of this information by building and testing new applications and climate services.

The session will cover dynamical as well as statistical predictions (including machine learning methods), and their combination. It will investigate predictions of various climate phenomena, including extremes, from global to regional scales, and from seasonal to multidecadal time scales ("seamless predictions"). Physical processes relevant to long-term predictability sources (e.g. ocean, cryosphere, or land) as well as predicting large-scale atmospheric circulation anomalies associated to teleconnections will be discussed, as will observational and emergent constraints on climate variability and predictability on the seasonal-to-(multi)decadal time scale. Also, the time-dependence of the predictive skill, or windows of opportunity (hindcast period), will be investigated. Analysis of predictions in a multi-model framework, and ensemble forecast initialization and generation, including innovative ensemble approaches to minimize initialization shocks, will be another focus of the session. The session will pay particular attention to innovative methods of quality assessment and verification of climate predictions, including extreme-weather frequencies, post-processing of climate hindcasts and forecasts, and quantification and interpretation of model uncertainty. We particularly invite contributions presenting the use of seasonal-to-decadal predictions for risk assessment, adaptation and further applications.

Large-scale atmospheric circulation, hydrological cycle and heat/moisture transports are tightly intertwined by global patterns of energy contrasts which are sensitive to multiple forcings and feedbacks. In the tropics, cross-equatorial energy exchanges by the ocean and atmosphere couple Hadley Circulation and Atlantic Overturning circulation, and modulate the low-level mass convergence and the amount of precipitation in the ITCZ and in monsoon regions. In the extra-tropics, Rossby waves affect the distribution of precipitation and eddy activity, shaping the meridional heat transport from the low latitudes towards the Poles.

We invite submissions addressing the interplay between Earth’s energy exchanges and the general circulation using modeling, theory, and observations. We encourage contributions on the forced response and natural variability of the general circulation, understanding present-day climate and past and future changes, and impacts of global features and change on regional climate.

The assessment of precipitation variability and uncertainty is crucial in a variety of applications, such as flood risk forecasting, water resource assessments, evaluation of the hydrological impacts of climate change, determination of design floods, and hydrological modelling in general. Within this framework, this session aims to gather contributions on research, advanced applications, and future needs in the understanding and modelling of precipitation variability, and its sources of uncertainty.
Specifically, contributions focusing on one or more of the following issues are particularly welcome:
- Novel studies aimed at the assessment and representation of different sources of uncertainty versus natural variability of precipitation.
- Methods to account for different accuracy in precipitation time series, e.g. due to change and improvement of observation networks.
- Uncertainty and variability in spatially and temporally heterogeneous multi-source precipitation products.
- Estimation of precipitation variability and uncertainty at ungauged sites.
- Precipitation data assimilation.
- Process conceptualization and modelling approaches at different spatial and temporal scales, including model parameter identification and calibration, and sensitivity analyses to parameterization and scales of process representation.
- Modelling approaches based on ensemble simulations and methods for synthetic representation of precipitation variability and uncertainty.
- Scaling and scale invariance properties of precipitation fields in space and/or in time.
- Physically and statistically based approaches to downscale information from meteorological and climate models to spatial and temporal scales useful for hydrological modelling and applications.

Changes in seasonal timing affect species and ecosystem response to environmental change. Observations of plant and animal phenology as well as remote sensing and modeling studies document complex interactions and raise many open questions.
We invite contributions with cross-disciplinary perspectives that address seasonality changes based on recent plant and animal phenological observations, pollen monitoring, historical documentary sources, or seasonality measurements using climate data, remote sensing, flux measurements or modeling studies. Contributions across all spatial and temporal scales are welcome that compare and integrate seasonality changes, study effects of long-term climate change or single extreme events, emphasize applications and phenology informed decision-making, discuss species interactions and decoupling, advance our understanding of how seasonality change affects carbon budgets and atmosphere/biosphere feedbacks, and integrate phenology into Earth System Models.
We emphasize phenology informed applications for decision-making and environmental assessment, public health, agriculture and forest management, mechanistic understanding of the phenological processes, and effects of changing phenology on biomass production and carbon budgets. We also welcome contributions addressing international collaboration and program-building initiatives including citizen science networks and data analyses.

This session is organized by a consortium representing the International Society of Biometeorology (Phenology Commission), the Pan-European Phenology Network - PEP 725, the Swiss Academy of Science SCNAT, the TEMPO French Phenology Network and the USA National Phenology Network.

Arid to sub-humid regions contribute > 40 % to the global land surface and are home of more than 40 % of the world’s population. During prehistoric times many important cultures had developed in these regions. Due to the high sensitivity of dryland areas even to small-scale environmental changes and anthropogenic activities, ongoing geomorphological processes but also the Late Quaternary palaeoenvironmental evolution as recorded in sediment archives are becoming increasingly relevant for geomorphological, palaeoenvironmental and geoarchaeological research. Dryland research is also boosted by methodological advances, and especially by emerging linkages with other climatic and geomorphic systems that allow using dryland areas as indicator-regions of global environmental change.
This session aims to pool contributions from the broad field of earth sciences that deal with geomorphological processes and different types of sediment archives in dryland areas (dunes, loess, slope deposits, fluvial sediments, alluvial fans, lake and playa sediments, desert pavements, soils, paleosols etc.) at different spatial and temporal scales. Besides case studies from individual regions and archives, methodical and conceptual contributions, e.g. dealing with the special role of eolian, fluvial, gravitational and biological processes in dryland environments, their preservation over time in the sedimentary records, and emerging opportunities and limitations to resolve past and current dynamics, are especially welcome in this session.

Groundwater is the world's most important, best protected and most exploited freshwater resource. It is intensively used by humans. It is also the primary source for drinking water supply and irrigation, hence critical to the global water-food-energy security nexus, especially in dry regions. Groundwater is sensitively to shifts in climate, which changes the hydrological cycle and thus groundwater recharge. Additionally, global changes such as population growth or changes in land use affect groundwater resources, both in terms of quantity and quality. Due to these changes, regions with high water stress are expected to expand globally. Beside regions that have already a water deficit, new regions, such as catchments in Central Europe with continental climate and decreasing precipitation in summer periods are likely to be subjected to water stress. The Mediterranean basin is also expected to become a major hot spot of water stress in the future.
Therefore, groundwater resources, especially in dry regions, need to be managed wisely, protected and especially used sustainably. In this session we invite contributions, which identify new consequences of a changing environment for better future management, protection, and sustainable use of groundwater. This implies adapted modelling techniques, such as coupling climate models with hydrological models, coupling climate models with soil water- and groundwater models. This includes also studies into groundwater quantity and quality changes and recharge mechanisms. In addition, we invite contributions from appropriate field observational studies.

Furthermore, the session asks for contributions that address regional strategies for groundwater sustainability, in detail that (i) unravel the combined action of topography, geology, climate, land use and anthropogenic forcing in controlling regional groundwater availability, quality and sustainability; and (ii) propose new methods (e.g., coupled modelling approaches) for assessing and managing regional groundwater systems in diverse climatic, hydrologic, socio-economic and institutional settings, and accounting for uncertainty; (iii) present appropriate field observational studies; (iv) address uncertainty and limited data availability due to a frequently associated data scarcity issue in dry regions, methodologies, strategies.

This session is linked to the Pan-Eurasian EXperiment (PEEX; www.atm.helsinki.fi/peex), a multi-disciplinary, -scale and -component climate change, air quality, environment and research infrastructure and capacity building programme. It is aimed at resolving major uncertainties in Earth system science and global sustainability issues concerning the Arctic, Northern Eurasia and China regions. This session aims to bring together researchers interested in (i) understanding environmental changes effecting in pristine and industrialized Pan-Eurasian environments (system understanding); (ii) determining relevant environmental, climatic, and other processes in Arctic-boreal regions (process understanding); (iii) the further development of the long-term, continuous and comprehensive ground-based, air/seaborne research infrastructures together with satellite data (observation component); (iv) to develop new datasets and archives of the continuous, comprehensive data flows in a joint manner (data component); (v) to implement validated and harmonized data products in models of appropriate spatio-temporal scales and topical focus (modeling component); (vi) to evaluate impact on society though assessment, scenarios, services, innovations and new technologies (society component).
List of topics:
• Ground-based and satellite observations and datasets for atmospheric composition in Northern Eurasia and China
• Impacts on environment, ecosystems, human health due to atmospheric transport, dispersion, deposition and chemical transformations of air pollutants in Arctic-boreal regions
• New approaches and methods on measurements and modelling in Arctic conditions;
• Improvements in natural and anthropogenic emission inventories for Arctic-boreal regions
• Physical, chemical and biological processes in a northern context
• Aerosol formation-growth, aerosol-cloud-climate interactions, radiative forcing, feedbacks in Arctic, Siberia, China;
• Short lived pollutants and climate forcers, permafrost, forest fires effects
• Carbon dioxide and methane, ecosystem carbon cycle
• Socio-economical changes in Northern Eurasia and China regions.
PEEX session is co-organized with the Digital Belt and Road Program (DBAR), abstracts welcome on topics:
• Big Earth Data approaches on facilitating synergy between DBAR activities & PEEX multi-disciplinary regime
• Understanding and remote connection of last decades changes of environment over High Asia and Arctic regions, both land and ocean.

It has been shown that regional climate change interacts with many other man-made perturbations in both natural and anthropogenic coastal environments. Regional climate change is one of multiple drivers, which have a continuing impact on terrestrial, aquatic and socio-economic (resp. human) environments. These drivers interact with regional climate change in ways, which are not completely understood. Recent assessments all over the world have partly addressed this issue (e.g. Assessment of Climate Change for the Baltic Sea region, BACC (2008, 2015); North Sea Climate Change Assessment, NOSCCA (2011); Canada’s Changing Climate Report, CCCR (2019)).
This session invites contributions, which focus on the connections and interrelations between climate change and other drivers of environmental change, be it natural or human-induced, in different regional seas and coastal regions. Observation and modelling studies are welcome, which describe processes and interrelations with climate change in the atmosphere, in marine and freshwater ecosystems and biogeochemistry, coastal and terrestrial ecosystems as well as human systems. In particular, studies on socio-economic factors like aerosols, land cover, fisheries, agriculture and forestry, urban areas, coastal management, offshore energy, air quality and recreation, and their relation to climate change, are welcome.
The aim of this session is to provide an overview over the current state of knowledge of this complicated interplay of different factors, in different regional seas and coastal regions all over the world.

ENSO and its interactions with other tropical basins are the dominant source of interannual climate variability in the tropics and across the globe. Understanding the dynamics, predictability, and impacts of ENSO and tropical basins interactions, and anticipating their future changes are thus of vital importance for society. This session invites contributions regarding all aspects of ENSO and tropical basins interactions, including: dynamics, multi-scale interactions; low frequency, decadal and paleo variability; theoretical approaches; ENSO diversity; global teleconnections; impacts on climate, society and ecosystems; seasonal forecasting and climate change projections of ENSO and its tropical basins interactions. Studies aimed at understanding ENSO and its tropical basins interactions in models of a range of complexity are especially welcomed, including analysis of CMIP model intercomparisons.

Agriculture is an important sector of any economy of the world. Agriculture productions are highly dependent on the climate change and variability. Changes in hydro-meteorological variables can influence crop yield and productivity at many places. Further, climate change can influence nutrient levels, soil moisture, water availability and other terrestrial parameters related to the agricultural productivity. Changes in the frequency and severity of droughts and floods could pose challenges for farmers and ranchers and threaten food safety. Further, changes in climate can influence meteorological conditions and thus can influence the crop growth pattern. It may also influence irrigation scheduling and water demand of the crops. The effects of climate change also need to be considered along with other evolving factors that affect agricultural production, such as changes in farming practices and technology.

The purpose of the proposed session is to gather scientific researchers related to this topic aiming to highlight ongoing researches and new applications in the field of climate change and agriculture. In this framework, original works concerned with the development or exploitation of advanced techniques for understanding the impact of climate change on agriculture will be invited.

The conveners of this session will encourage both applied and theoretical research in this area.

Weather and Climate Services (WCS) involve the production, translation, delivery, and use of science-based information for decision-making. The production of WCS makes use of long-term climate projections, climate and weather predictions from daily to decadal timescales, historical hydrometeorological data, and sectoral models to predict risks of climate impacts to society. These services are developed and delivered in support of (i) climate-sensitive sectors such as agriculture, management of water resource, health, energy and disaster risk reduction, and (ii) developing countries where the vulnerability to climate change and extreme weather events is high. This session, interdisciplinary in nature, aims at showcasing tools, products and methodologies that could be standardized for an operational and innovative system of WCS delivery in developing countries. The session invites contributions that include a) improvements of models and data analysis for WCS; b) engagement with end-users of WCS; c) assessment of the value of WCS’s outcomes and the corresponding impacts on societies and the environment; d) strategies for broad communication of WCS information to multiple audiences; and e) WCS partnerships between multiple stakeholders such as end-users, NGOs, government ministries, policymakers, and the private sector. The session particularly encourages lessons learned and results from different case studies coming from the global South.

Regional Climate Models (RCMs) have become fundamental tools to study climate processes and
climate change projections at the regional to local scale, and the COordinated Regional Downscaling EXperiment (CORDEX) has become a central program within the RCM modeling community. This session accepts papers on a wide range of topics pertaining the field regional climate modeling and applications, including: recent developments in RCM science; added value of RCMs; applications of RCMs to regional climate change projection; development and application of coupled regional Earth System Models (including interactive atmosphere, ocean, chemistry/aerosol, biosphere and cryosphere components); development and application of convection-permitting RCMs; completion and/or analysis of CORDEX experiments, both single model simulations and multi-model ensembles; completion and/or analysis of experiments within the CORDEX-CORE and CORDEX Flagship Pilot Studies programs; application of RCM output to vulnerability, impacts and adaptation studies; application of RCMs to climate service activities.

Anthropogenic aerosol plays a key role in driving climate anomalies over a range of spatial and temporal scales, both near the emission location and remotely through teleconnections. Aerosols can interact with radiation and clouds, directly and through absorption, microphysics and circulation, and thereby modify the surface and atmospheric energy balance, cloud dynamics and precipitation patterns, and the atmospheric and oceanic circulation. This session addresses progress in understanding the mechanisms and pathways by which aerosols affect regional climate features, overall, over the historical era, and in the near future. We encourage contributions on new model and observation-based approaches to investigate the effects of aerosols on regional decadal climate variability and extremes, tropical-extratropical interactions and teleconnections, and the interplay with modes of variability such as the NAO, AMO, and PDO. Focus studies on monsoon, midlatitude, and Arctic responses, extreme precipitation, circulation changes, daily variability, CMIP6 projections of high and low aerosol futures, and investigations using large ensemble simulations are welcome.

In this session, we invite presentations that investigate CMIP6 (or other, similarly co-ordinated) simulations.

Analysis of the Sixth Coupled Model Intercomparison Project (CMIP6) is now well underway. Here, we focus on analyses of coordinated simulations undertaken through, or parallel to, the CMIP protocol, with a particular focus on historical simulations and future projections. We are particularly interested in analyses that involve a role for the North Atlantic region, either in evaluating/describing simulated/projected variability or in the North Atlantic’s remote effect on other regions. We are interested in (multi)model evaluation, mechanisms of variability, as well as impact analysis. Multimodel analyses are especially welcome as are critical comparisons between models and observations.

We invite presentations that investigate CMIP (or similarly co-ordinated) simulations on topics including, but not limited to, the following:

-o- The historical and future evolution of the Atlantic Meridional Overturning Circulation (AMOC)
-o- Projected changes in the strength and location of the jet stream
-o- Atlantic Multidecadal Variability (AMV), including future changes and the role of internally/externally forced variability
-o- Projections or mechanisms of changes in hurricane activity
-o- The drivers and impacts of Arctic ice melt
-o- The hydrological cycle and freshening of the North Atlantic, including “hosing” simulations
-o- Teleconnections between the North Atlantic and remote regions including over land

Mediterranean climate is characterized by mild, wet winters and hot, dry summers thus making the interested climatic zones among the most desirable for human inhabitation. Mediterranean climate zones are located in transitional midlatitude regions like the Mediterranean basin area, western North America as well as over small areas of western South America, Southern Africa and southern Australia. This classification based on Koppen-Geiger approach is well suited for identifying and analyzing the impacts of climate change on natural and anthropic ecosystems. The transitional character with sharp spatial gradients makes Mediterranean climate-type zones highly vulnerable to climate change. Future climate projections indicate an intensification of the seasonality over these regions, as well as potential migration of these climate regions towards the poles with the equatorward margins likely replaced by arid climate-type. For all mediterranean climate-type regions, the future is expected to provide large issues to face for biodiversity and water availability, including climate adaptation and mitigation measures.
This session aims bringing together studies on different aspects of climate and climate change focused on the Mediterranean climate-type regions of the world. Physical (including extremes, teleconnections, hydrological cycles) and biogeochemical (including biodiversity) approaches but also social aspects (including impacts and adaptation measures) are welcome, either in terms of observed past changes or future climate projections.

Solicited Speaker will be Prof Don McFarlane - School of Agriculture and Environment, University of Western Australia

As highlighted by the UN development goals, climate change is a reality to which we need to adapt. Our ability to effectively address the adaptation issue must come from a communal effort to link our knowledge in different fields and transform it into useful information for stakeholders and policymakers.

Up to now, physical climate modelling and natural hazard impact and risk assessment have been two separate disciplines that have suffered difficulties in communicating and interacting due to different languages and backgrounds. Until recently, climate modellers did not have the capability to generate long-term projections at a spatial and temporal resolution useful for impact studies such as flood risk assessment, soil erosion or urban modelling. With the advent of kilometre-scale atmospheric models, called convection-permitting models CPMs, we are now in a position to bridge the gap between the two communities, sharing knowledge and understanding. Compared to traditional climate models, CPMs improve substantially the representation of sub-daily precipitation characteristics and have a spatial resolution closer to what many impacts modellers, for example hydrologists, need. Several CPM datasets are already available over different parts of the world and more internationally coordinated projects on CPMs, such as the CORDEX Flagship Pilot Study (CORDEX-FPS) and the European Climate Prediction System (EUCP), are already in place. Now is the time to exploit these high-resolution physically-consistent datasets as input for impact studies and adaptation strategies; to foster interdisciplinary collaboration to build a common language and understand limitations and needs of the different fields; to learn together how to provide policymakers with information and practical cases that can be used to design effective measures at the regional level to adapt to climate change as well as to inform mitigation decisions.

This interdisciplinary session invites contributions that address the linkages between high-resolution modellers and users with examples of good practice, storylines and communication to both stakeholders and policymakers.

Detecting and attributing the fingerprint of anthropogenic climate change in long-term observed climatic trends is an active area of research. Though the science is well established for temperature related variables, the study of other climate indicators including hydrometeorological variables pose greater challenges due to their greater complexity and rarity.

Complementary to this, assessing the extent to which extreme weather events, including compound events, are attributable to anthropogenic climate change is a rapidly developing science, with emerging schools of thought on the methodology and framing of such studies. Once again, the attribution of hydrometeorological events, is less straightforward than temperature-related events. The attribution of impacts, both for long-term trends and extreme events is even more challenging.

This session solicits the latest studies from the spectrum of detection and/or attribution approaches. By considering studies over a wide range of temporal and spatial scales we aim to identify common/new methods, current challenges, and avenues for expanding the detection and attribution community. We particularly welcome submissions that compare approaches, or address hydrometerological trends, extremes and/or impacts – all of which test the limits of the present science.

One of the big challenges in Earth system science consists in providing reliable climate predictions on sub-seasonal, seasonal, decadal and longer timescales. The resulting data have the potential to be translated into climate information leading to a better assessment of multi-scale global and regional climate-related risks.
The latest developments and progress in climate forecasting on subseasonal-to-decadal and longer timescales will be discussed and evaluated. This will include presentations and discussions of predictions for a time horizon of up to ten years from dynamical ensemble and statistical/empirical forecast systems, as well as the aspects required for their application: forecast quality assessment, multi-model combination, bias adjustment, downscaling, etc.
Following the new WCPR strategic plan for 2019-2029, prediction enhancements are solicited from contributions embracing climate forecasting from an Earth system science perspective. This includes the study of coupled processes, impacts of coupling and feedbacks, and analysis/verification of the coupled atmosphere-ocean, atmosphere-land, atmosphere-hydrology, atmosphere-chemistry & aerosols, atmosphere-ice, ocean-hydrology, ocean-ice, ocean-chemistry and climate-biosphere (including human component). Contributions are also sought on initialization methods that optimally use observations from different Earth system components, on assessing and mitigating the impacts of model errors on skill, and on ensemble methods.
We also encourage contributions on the use of climate predictions for climate impact assessment, demonstrations of end-user value for climate risk applications and climate-change adaptation and the development of early warning systems.

A special focus will be put on the use of operational climate predictions (C3S, NMME, S2S), results from the CMIP5-CMIP6 decadal prediction experiments, and climate-prediction research and application projects (e.g. EUCP, APPLICATE, PREFACE, MIKLIP, MEDSCOPE, SECLI-FIRM, S2S4E, CONFESS).
An increasingly important aspect for climate forecast's applications is the use of most appropriate downscaling methods, based on dynamical or statistical approaches or their combination, that are needed to generate time series and fields with an appropriate spatial or temporal resolution. This is extensively considered in the session, which therefore brings together scientists from all geoscientific disciplines working on the prediction and application problems.

In 2015, the UN Sustainable Development Goals and the Paris Agreement on climate recognised the deteriorating resilience of the Earth system, with planetary-scale human impacts constituting a new geological epoch: the Anthropocene. Earth system resilience critically depends on the nonlinear interplay of positive and negative feedbacks of biophysical and increasingly also socio-economic processes. These include dynamics in the carbon cycle, large-scale ecosystems, atmosphere, ocean, and cryosphere that can absorb geophysical shocks (e.g. volcanic eruptions), as well as the dynamics and perturbations associated with human activities.

Maintaining Earth in the Holocene-like interglacial state within which the world’s societies evolved over the past ~10,000 years will require industrialised societies to embark on rapid global-scale socio-economic transformations. In addition to incrementally increasing environmental hazards, there is a risk of crossing tipping points in the Earth system triggering partly irreversible and potentially cascading changes.

In this session we invite contributions on all topics relating to Earth resilience, such as assessing the biophysical and social determinants of the Earth’s long-term stability, negative feedback processes, modelling and data analysis and integration of nonlinearity, tipping points and abrupt shifts in the Earth system, and the potential for rapid social transformations to global sustainability.

Soil organic matter (SOM) is well known to exert a great influence on physical, chemical, and biological soil properties, thus playing a very important role in agronomic production and environmental quality. Globally SOM represents the largest terrestrial organic C stock, which can have significant impacts on atmospheric CO2 concentrations and thus on climate. The changes in soil organic C content are the result of the balance of inputs and losses, which strongly depends on the processes of organic C stabilization and protection from decomposition in the soil. This session will provide a forum for discussion of recent studies on the stabilization and sequestration mechanisms of organic C in soils, covering any physical, chemical, and biological aspects related to the selective preservation and formation of recalcitrant organic compounds, occlusion by macro and microaggregation, and chemical interaction with soil mineral particles and metal ions.

The session asks for well-dated geoarchives that document the physical evidence of the transition from the Late Holocene (Meghalayan) to the Anthropocene. These may include artificial deposits, lake, estuary or marine sediments, peat, speleothems, ice core or biological hosts such as trees or corals, displaying good chronologies. The evidence for an Anthropocene can include transitions in the types and abundance of physical materials, biota, or distinct geochemical signals; ideally the study should provide multiple proxies or consider innovative new techniques in recognising the Anthropocene. We are interested in presentations that show continuous to near continuous records that can extend hundreds or even thousands of years back in time, but should also include comparable analysis through the mid-20th century to near present day. The presentations should explain how, if at all, the Anthropocene can be distinguished in these archives. Studies from any continent will be considered, though presentations on archives from South America and Africa are especially encouraged.

Documenting the diversity of human responses and adaptations to climate, landscapes, ecosystems, natural disasters and the changing natural resources availability in different regions of our planet, cross-disciplinary studies in Geoarchaeology provide valuable opportunities to learn from the past. Furthermore, human activity became a major player of global climatic and environmental change in the course of the late Quaternary, during the Anthropocene. Consequently, we must better understand the archaeological records and landscapes in context of human culture and the hydroclimate-environment nexus at different spatial and temporal scales. This session seeks related interdisciplinary papers and specific geoarchaeological case-studies that deploy various approaches and tools to address the reconstruction of former human-environmental interactions from the Palaeolithic period through the modern. Topics related to records of the Anthropocene from Earth and archaeological science perspectives are welcome. Furthermore, contributions may include (but are not limited to) insights about how people have coped with environmental disasters or abrupt changes in the past; defining sustainability thresholds for farming or resource exploitation; distinguishing the baseline natural and human contributions to environmental changes. Ultimately, we would like to understand how strategies of human resilience and innovation can inform our modern strategies for addressing the challenges of the emerging Anthropocene, a time frame dominated by human modulation of surface geomorphological processes and hydroclimate.

Nature-based Solutions (NBS) are reframing discussion and policy responses worldwide to environmental challenges. Thus, NBS is of growing implementation, supported namely by the EU political agenda (e.g., green deal), as a way to attain the United Nations (UN) Sustainable Development Goals (SDG), and to reinforce the New Urban Agenda. The NBS concept recognise the importance of nature and outline requirements for a systemic and holistic approach to environmental change, based on an understanding of the structure and functioning of ecosystems, and the social and institutional context within which they are situated. Furthermore, there is a growing recognition that human activities exert pressure on natural resources affecting the ecosystem dynamics and therefore the nexus (synergies and trade-offs) between their different functions and services. However, quantification of existing NBS’ effectiveness, their operationalisation and replication in different environmental settings has not been presented in such a way that allows them to be both widely accepted and incorporated in policy development and in practical implementation to achieve the UN SDGs.
This session aims to discuss and advance knowledge of innovative NBS approaches to face environmental challenges, such as water supply and management, agricultural production and healthy ecosystems, and simultaneously provide better understanding of associated social-ecological interactions, contributing to enhance the scientific basis for sustainable development and resilience.
This session seeks to:
- Better understanding of advantages and disadvantages of NBS to address global environmental and societal challenges;
- Studies on adaptation and mitigation options for the effect of climate change on water provisioning and livelihoods;
- New methods and tools to investigate the role of NBS in the context of environmental change; in particular, the effectiveness of NBS for hydro-meteorological risk reduction at landscape/watershed scale;
- New insights, methodologies, tools and best practices enabling successful implementation and upscaling of NBS in multiple contexts;
- Identifying opportunities for and barriers to NBS within current regulatory frameworks and management practices;
- Presenting overviews and case studies of NBS projects that also involve the private sector and market-based mechanisms;
- NBS towards achieving the Sustainable Development Goals (SDGs).

Natural disturbances in forests, including windthrow events, insect infestations, wildfires and droughts have intensified in severity, frequency, and extent over the last few decades, and ongoing climate change is predicted to further accelerate these trends. If disturbance regimes exceed ecosystem resilience thresholds, forests may change to a new permanent state (e.g. turnover of tree species composition) or may convert fully into non-forest ecosystems.

Forest management practices can influence both the resistance and resilience of a forest ecosystem to its disturbances, in terms of outcomes for biodiversity, nutrient cycling, and the biochemical and physical properties of landscapes. Promotion of mixed species forestry, for instance, can increase stand stability against windthrow, and might decrease forests’ vulnerability to insect attacks or drought. Retention of dead wood, on the other hand, is thought to enhance the recovery of forest structure and complexity, as well as above and below-ground diversity. Type, scale and intensity of disturbance events, along with pre- and post-disturbance management practices, may ultimately lead to changes in vegetation dynamics and plant-soil-atmosphere interactions.

In this session, we hope to stimulate scientific exchange among ecological research disciplines, broaden the view on how forest management shapes forest susceptibility to natural disturbances, and draw attention to how management can alleviate post-disturbance effects on ecosystem functioning. We aim to bring together research spanning from tree and soil processes at the microscale to landscape-level dynamics. We invite contributions investigating natural forest disturbances and pre- and post-disturbance management practices from a variety of perspectives, including:
• Vegetation dynamics;
• Micro-meteorology;
• Plant physiology;
• Soil sciences;
• Microbiology.

Contributions based on observational, experimental, and modeling studies as well as reviews and syntheses are welcome.

Extreme climate and weather events, associated disasters, geohazards and emergent risks interact with other stressors, especially growing anthropogenic pressures, and are so becoming increasingly critical in the context of global environmental change. They are a potential major threat to reaching the Sustainable Development Goals (SDGs) and one of the most pressing challenges for future human well-being and safety.
This session explores the linkages between extreme climate and weather events, geohazards, associated disasters, societal dynamics and resilience.
Emphasis is laid on 1) Which impacts are caused by extreme climate events (including risks emerging from compound events) and cascades of impacts on various aspects of ecosystems and societies? 2) Which feedbacks across ecosystems, infrastructures and societies exist? 3) What are key obstacles towards societal resilience and reaching the SDGs, while facing climate extremes? 4) What can we learn from past experiences? 5) What local to global governance arrangements best support equitable and sustainable risk reduction?
Nowadays, to answer this last question, the careful application of social media and crowdsourcing (SMCS) begins to make a contribution, notably in the field of geosciences. SMCS have been integrated into crisis and Disaster Risk Management (DRM) for improved information gathering and collaboration across communities, and for collaboratively coping with critical situations. Numerous governments and EU-funded projects have been exploring the implementation and use of SMCS by developing and adopting new technologies, procedures, and applications. The effectiveness of SMCS on European disaster resilience, however, remains unclear, due to the diversity among disaster risk perception and vulnerability. In general, this second part addresses ways to govern and understand the effectiveness of SMCS for Disaster Risk Management and the related Disaster Resilience is focused.
In this session we welcome empirical with practical applications, theoretical and modelling studies from local to global scale from the fields of natural sciences, social sciences, humanities and related disciplines since the creation of novel effective approaches necessitates a coordinated and coherent effort between them.

Hydroclimatic conditions and the availability of water resources in space and time constitute important factors for maintaining an adequate food supply, the quality of the environment, and the welfare of inhabitants, in the context of sustainable growth and economic development. This session is designed to explore the impacts of hydroclimatic variability, climate change, and the temporal and spatial availability of water resources on: food production, population health, the quality of the environment, and the welfare of local ecosystems. We particularly welcome submissions on the following topics:

- Complex inter-linkages between hydroclimatic conditions, food production, and population health, including: extreme weather events, surface and subsurface water resources, surface temperatures, and their impacts on food security, livelihoods, and water- and food-borne illnesses in urban and rural environments.
- Quantitative assessment of surface-water and groundwater resources, and their contribution to agricultural system and ecosystem statuses.
- Spatiotemporal modeling of the availability of water resources, flooding, droughts, and climate change, in the context of water quality and usage for food production, agricultural irrigation, and health impacts over a wide range of spatiotemporal scales.
- Intelligent infrastructure for water usage, irrigation, environmental and ecological health monitoring, such as development of advanced sensors, remote sensing, data collection, and associated modeling approaches.
- Modelling tools for organizing integrated solutions for water, precision agriculture, ecosystem health monitoring, and characterization of environmental conditions.
- Water re-allocation and treatment for agricultural, environmental, and health related purposes.
- Impact assessment of water-related natural disasters, and anthropogenic forcings (e.g. inappropriate agricultural practices, and land usage) on the natural environment; e.g. health impacts from water and air, fragmentation of habitats, etc.

The global cryosphere with all its components is strongly impacted by climate change and has been undergoing significant changes over the past decades. Glaciers are shrinking and thinning. Snow cover and duration is reduced, and permafrost, in both Arctic and mountain environments, is thawing. Changes in sea ice cover and characteristics have attracted widespread attention, and changes in ice sheets are monitored with care and concern. Risks associated with one or several of these cryosphere components have been present throughout history. However, with ongoing climate change, we expect changes in the magnitude and frequency of hazards with profound implications for risks, especially when these interact with other aspects relating to context vulnerability, exposure, and other processes of biophysical and/or socioeconomic drivers of change. New or growing glacier lakes pose a threat to downstream communities through the potential for sudden drainage. Thawing permafrost can destabilize mountain slopes, and eventually result in large landslide or destructive rock and ice avalanches. An accelerated rate of permafrost degradation in low-land areas poses risk to existing and planned infrastructure and raises concerns about large-scale emission of greenhouse gases currently trapped in Arctic permafrost. Decreased summertime sea ice extent may produce both risks and opportunities in terms of large-scale climate feedbacks and alterations, coastal vulnerability, and new access to transport routes and natural resources. Furthermore, rapid acceleration of outlet glacier ice discharge and collapse of ice sheets is of major concern for sea level change. This session invites contributions across all cryosphere components that address risks associated with observed or projected physical processes. Contributions considering more than one cryosphere component (e.g. glaciers and permafrost) are particularly encouraged, as well as contributions on cascading processes and interconnected risks. Contributions can consider hazards and risks related to changes in the past, present or future. Furthermore, Contributions may consider one or several components of risks (i.e. natural hazards, exposure, vulnerability) as long as conceptual clarity is ensured. Furthermore, cases that explore diverse experiences with inter- and transdisciplinary research, that sought to address these risks with communities through adaptation and resilience building, are also be considered.

Climate change (CC) is the greatest threat to humanity and to Earth’s biodiversity, and affects every single living being and every ecological niche, with poorer communities suffering disproportionately. Many geosciences are thus directly confronted by CC. Geoethics provides an ethical framework to address such challenges to a sustainable future.

However, relatively little is being done to provide opportunities to help people round the world to learn about the changes that are affecting their and their offspring’s lives. The more people are knowledgeable about the changes affecting their lives, the more they will be able to make informed decisions and to adapt and mitigate. In the wake of the 2020 EGU Declaration of the Significance of Geoscience, it is clear that Climate Literacy/Learning (CL) is an imperative that needs to be addressed massively and urgently, both within and beyond the EGU. Geosciences and geoethics can play a significant role in furthering CL.

CL has developed in recent years. Areas of improvement include school curricular, teacher training, educational games, citizen initiatives and EGU sessions, such as the pioneering 2018 and 2019 Climate Change Education sessions. However, much work still needs to be done, for example, to make CL an essential component in all subjects, and at all levels throughout the education system. The aims of such CL might include encouraging an intergenerational outlook, developing a sense of the geoethical dimensions of CC, understanding the complexities and finding solutions acceptable to a broad range of stakeholders. In the poorer parts of the world, where CC impact is greatest and resources are scarce, CL is in its infancy and even more urgent.

We invite colleagues to submit contributions on any aspects of climate literacy – on learning processes, instructional materials, learning methods and experiences, and curricular innovation to promote greater CL. The full spectrum of CC science that might be covered by CL can be included, such as GHGs, reinforcing feedback, energy systems, heatwaves, sea-level rise, oceans, carbon cycle, ice melt, communication, attitudes, gender issues, health, political influence, activism, behavioural change and geoethics. The session is an opportunity for people (ECSs, scientists, educators, policy influencers, learning resource developers and other experts) to share their experience, expertise and research on effective ways of improving CL, to better fight CC.

World-wide an increasing number of research projects focus on the challenges associated with changes in the Arctic regions. Whereas these often have a natural and physical science focus, this session focuses on trans-disciplinary approaches to study the multiple phenomena associated with global warming, especially but not exclusively in Arctic regions. Another focus is to understand better how to tackle these in large, trans-disciplinary research projects, initiatives and programs (e.g. HORIZON2020 Nunataryuk, INTAROS and the T-MOSAIC program of the International Arctic Research Council, NSF Navigating the New Arctic), as well as communicating results effectively to the public in terms of outreach and education. Contributions are invited, but are not limited, to the following themes:
• science communication, education and outreach tools, and co-production of knowledge
• integration of social and natural science approaches
• indigenous and collaborative approaches to adaptation and mitigation, equitable mitigation, and risk perception
• socio-economic modelling in relation to Arctic environmental change,
• examining the impacts of permafrost thaw and other phenomena on health and pollution as well as infrastructure (and consequences of the built environment).

One of the aims of this session is to bring together researchers from both social and natural sciences who are involved or interested in reaching out to stakeholders and the general public, and share successful experiences. Examples from past, ongoing and future initiatives that include traditional indigenous knowledge and scientific tools and techniques are welcome.

We are also excited to let you know that our ERL special issue called 'Focus on Arctic Change: Transdisciplinary Research and Communication’ is now open for submission. See the webpage: https://iopscience.iop.org/journal/1748-9326/page/Focus_on_Arctic_Change_Transdisciplinary_Research_and_Communication Please consider submitting your manuscript until or preferably before the 31st of May 2021.

Citizen science (the involvement of the public in scientific processes) is gaining momentum across multiple disciplines, increasing multi-scale data production on Earth Sciences that is extending the frontiers of knowledge. Successful participatory science enterprises and citizen observatories can potentially be scaled-up in order to contribute to larger policy strategies and actions (e.g. the European Earth Observation monitoring systems), for example to be integrated in GEOSS and Copernicus. Making credible contributions to science can empower citizens to actively participate as citizen stewards in decision making, helping to bridge scientific disciplines and promote vibrant, liveable and sustainable environments for inhabitants across rural and urban localities.
Often, citizen science is seen in the context of Open Science, which is a broad movement embracing Open Data, Open Technology, Open Access, Open Educational Resources, Open Source, Open Methodology, and Open Peer Review. Before 2003, the term Open Access was related only to free access to peer-reviewed literature (e.g., Budapest Open Access Initiative, 2002). In 2003 and during the “Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities”, the definition was considered to have a wider scope that includes raw research data, metadata, source materials, and scholarly multimedia material. Increasingly, access to research data has become a core issue in the advance of science. Both open science and citizen science pose great challenges for researchers to facilitate effective participatory science, yet they are of critical importance to modern research and decision-makers. To support the goals of the various Open Science initiatives, this session looks at what is possible and what is applied in Earth Science.

We want to ask and find answers to the following questions:
Which approaches can be used in Earth Sciences?
What are the biggest challenges in bridging between scientific disciplines and how to overcome them?
What kind of participatory citizen scientist involvement and open science strategies exist?
How to ensure transparency in project results and analyses?
What kind of critical perspectives on the limitations, challenges, and ethical considerations exist?

The pressure of human activities on the Earth System has reached a scale where abrupt global environmental changes can no longer be excluded and gradual changes are accelerating at alarming rates. Simply continuing established political efforts to “decouple” GDP from resource use and GHG emissions will not suffice to achieve the absolute reductions required to avoid catastrophic climate change and reduce rising pressures on ecosystems. Hence, a socioecological transformation of resource use patterns is required that will imply significant non-linear deviations from past trajectories.
The question then arises, to what extent and how societies actually have agency to actively shape, accelerate and steer such a required transformation? Human agency refers to the ability to shape one’s life, or the collective ability to change the course of social action. Individual agency is reflected in individual choices and the ability to influence one’s life conditions and chances. Collective agency refers to situations in which individuals pool their knowledge, skills, and resources, and act in concert to shape their future.
Complex systems, such as our planet and human societies, cannot be fully controlled and their behaviour cannot be predicted. Nevertheless, some authors argue it possible to imperfectly navigate such systems. The questions that we are going to discuss in the session include:
i. How to navigate the humanity in the Anthropocene?
ii. What are the relevant dimensions of human agency to study human-environment system interactions?
iii. Which concepts and research methods are relevant for the research on human agency?
iv. How to operationalize human agency in global human-environmental system modelling efforts?
We are in particular interested in new approaches that would go beyond the rational choice and equilibrium paradigms. Such approaches should be able to explain and demonstrate system evolution pathways, system transitions, tipping points, and tipping interventions. They should be able to include human agents who operate under the conditions of resource scarcity and conflicting interests, and take decisions in the presence of high risk and uncertainty.

The UN 2030 Agenda for Sustainable Development is an urgent call for a global partnership for action. The new paradigm of the Paris Agreement puts additional responsibility on scientists to provide data and knowledge to inform climate action for the benefit of society. Together with the other UN conventions (on biological diversity and on disaster risk reduction), these frameworks are highly dependent on evidence-based information derived from geosciences. After having developed crucial capacities on the regional level, Research Infrastructures and other data providers need to upgrade their cooperation efforts and coordinate their actions on the global level. They must ensure a sustainable production of data, products and services in line with the demands of the decision-makers. To deliver on the expectations of the UN system in support of policy-makers, actors from different disciplines (observation, modeling, reporting…) have to intensify their collaborative efforts.

In this session, we welcome abstracts presenting the recent developments in international cooperation efforts, global integration of data sets, initiatives to support climate services and especially the Monitoring, Reporting and Verification mechanism of the Paris Agreement. We also wish to stage the role of disciplines belonging to the human and social fields in achieving the objective.

Remaining carbon budgets specify the maximum amount of CO2 that may be emitted to stabilize warming at a particular level (such as the 1.5 °C target), and are thus of high interest to the public and policymakers. Yet, there are many sources of uncertainty which make it challenging to estimate the remaining carbon budget in real world conditions, especially for ambitious mitigation targets.

This session aims to further our understanding of the climate response under different emission scenarios, with particular interest in emission pathways towards net-zero targets, and to advance our knowledge of associated carbon budgets consistent with meeting various levels of warming. We invite contributions that use a variety of tools, including fully coupled Earth System Models, Integrated Assessment Models, or simple climate model emulators.

We welcome studies exploring different aspects of climate change in response to future emission scenarios, in addition to studies exploring carbon budgets and the TCRE framework, including: the governing mechanisms behind linearity of TCRE and its limitations, effects of different forcings and feedbacks (e.g. permafrost carbon feedback) and non-CO2 forcings (e.g. aerosols, and other non-CO2 greenhouse gases), estimates of the remaining carbon budget to reach a given temperature target (for example, the 1.5 °C warming level from the Paris Agreement), the role of pathway dependence and emission rate, the climate-carbon responses to different emission scenarios (e.g. SSP scenarios, idealized scenarios, or scenarios designed to reach net-zero emission level), and the behaviour of TCRE in response to artificial carbon dioxide removal from the atmosphere (i.e. CDR or negative emissions). Contributions from the fields of climate policy and economics focused on applications of carbon budgets and benefits of early mitigation are also encouraged.

Understanding the impact of climate change on natural and socio-economic outcomes plays an important role in informing a range of national and international policies, including energy, agriculture and health. Furthermore, studying this interplay between natural and human systems sheds light on progress and future challenges required to achieve many of the UN Sustainable Development Goals. However economic models of (and those designed to include) climate impacts that guide decision makers rely on multiple components, for example projections of future climate change, damage functions, and policy responses, each of which comes with its own modelling challenges and uncertainties.

We invite research using process-based (e.g. Integrated Assessment Models) and empirical models of climate change to investigate future human and natural impacts, together with policy evaluation to explore effective mitigation, technology and adaptation pathways. Furthermore, we invite research on changes to, and new developments of climate-economic and econometric modelling.

One of the most challenging sustainable goals of the UN 2030 Agenda and other international agreements is that urban systems have to increase well-being and health. Indeed, these networked systems already host more than half of the world's population and are going to host most of its growth, while they have been mostly designed and managed with limited visions, in particular with respect to their geophysical environment.
This goal got an unforeseen acuity with the Covid-19 pandemic, starting with the confinement strategies that radically brought into question the functioning of these systems, e.g., drastically reducing mobility and breaking its ever increasing trend. Covid-19 was not without precursor (e.g., SARS, MERS) and will not be without successors.

Long term visions based on transdisciplinary scientific advances are therefore indispensable, particularly from the geoscience community. As a consequence, this session calls for contributions from data-driven and theory-driven approaches of urban health under global change. This includes:
- qualitative improvements of epidemic modelling, as trans-disciplinary and nonlinear as possible
- possible interplays between meteorological and/or climate drivers and epidemic/health issues
- novel monitoring capabilities (including contacts tracking), data access, assimilation and multidimensional analysis techniques
- managing field works, geophysical monitoring and planetary missions
- how to have the highest science output during corona pandemic
- a fundamental revision of our urban systems, their greening as well as their mobility offer
- a particular focus on urban biodiversity, in particular to better manage virus vectors
- urban resilience must include resilience to epidemics, and therefore requires revisions of urban governance.

To address societal concerns over rising sea level and extreme events, understanding the contributions behind these changes is key to predict potential impacts of sea level change on coastal communities and global economy, and is recognized as one of the Grand Challenges of our time by the World Climate Research Programme (WCRP). To continue this discussion, we welcome contributions from the international sea level community that improve our knowledge of the past and present changes in sea level, extreme events, and flooding, and produce improved predictions of their future changes. We welcome studies on various drivers of sea level change and linkages between variability in sea level, heat and freshwater content, ocean dynamics, land subsidence from natural versus anthropogenic influences, and mass exchange between the land and the ocean associated with ice sheet and glacier mass loss and changes in the terrestrial water storage. Studies focusing on future sea level changes are also encouraged, as well as those discussing potential short-, medium-, and long-term impacts on coastal and deltaic environments, as well as the global oceans.

The largest single source of uncertainty in projections of future global sea level is associated with the mass balance of the Antarctic Ice Sheet (AIS). In the short-term, it cannot be stated with certainty whether the mass balance of the AIS is positive or negative; in the long-term, the possibility exists that melting of the coastal shelves around Antarctica will lead to an irreversible commitment to ongoing sea level rise. Observational and paleoclimate studies can help to reduce this uncertainty, constraining the parameterizations of physical processes within ice sheet models and allowing for improved projections of future global sea level rise. This session welcomes presentations covering all aspects of observation, paleoclimate reconstruction and modeling of the AIS. Presentations that focus on the mass balance of the AIS and its contribution towards changes in global sea level are particularly encouraged.

Ice sheets play an active role in the climate system by amplifying, pacing, and potentially driving global climate change over a wide range of time scales. The impact of interactions between ice sheets and climate include changes in atmospheric and ocean temperatures and circulation, global biogeochemical cycles, the global hydrological cycle, vegetation, sea level, and land-surface albedo, which in turn cause additional feedbacks in the climate system. This session will present data and modelling results that examine ice sheet interactions with other components of the climate system over several time scales. Among other topics, issues to be addressed in this session include ice sheet-climate interactions from glacial-interglacial to millennial and centennial time scales, the role of ice sheets in Cenozoic global cooling and the mid-Pleistocene transition, reconstructions of past ice sheets and sea level, the current and future evolution of the ice sheets, and the role of ice sheets in abrupt climate change.

The evolution of the large ice sheets and the Earth’s rheology control the process of glacial isostatic adjustment, while bedrock topography and geothermal heat flux have strong feedbacks on ice sheet dynamics. For changing climates, this interplay exerts a fundamental control on the global and regional sea level and, in turn, influences ice sheet stability.

In this session, we focus on feedback mechanisms between climate relevant components, such as ice sheets, ice shelves, solid Earth, oceans and atmosphere (e.g., as in the German Climate modelling initiative PalMod). We invite global, regional and conceptual studies that consider reconstructions of the past and/or estimates of future ice sheet evolution in fields related to the climate system dynamics of glacial processes (the cryosphere, geosphere, oceanography, climatology, geodesy and geomorphology). In particular, we welcome studies of recent and paleo observations (geodetic, geological, geophysical), coupled numerical modelling and strategies, data-constrained model calibration and data assimilation.

Atmosphere and Cryosphere are closely linked and need to be investigated as an interdisciplinary subject. Most of the cryospheric areas have undergone severe changes in last decades while such areas have been more fragile and less adaptable to global climate changes. This AS-CR session invites model- and observational-based investigations on any aspects of linkages between atmospheric processes and snow and ice on local, regional and global scales. Emphasis is given on the Arctic, high latitudes and altitudes, mountains, sea ice, Antarctic regions. In particular, we encourage studies that address aerosols (such as Black Carbon, Organic Carbon, dust, volcanic ash, diatoms, bioaerosols, bacteria, etc.) and changes in the cryosphere, e.g., effects on snow/ice melt and albedo. The session also focuses on dust transport, aeolian deposition, and volcanic dust, including health, environmental or climate impacts at high latitudes, high altitudes and cold Polar Regions. We include contributions on biological and ecological sciences including dust-organisms interactions, cryoconites, bio-albedo, eco-physiological, biogeochemical and genomic studies. Related topics are light absorbing impurities, cold deserts, dust storms, long-range transport, glaciers darkening, polar ecology, and more. The scientific understanding of the AS-CR interaction needs to be addressed better and linked to the global climate predictions scenarios.

One of the most striking features of global climate change is the strongly amplified response of surface air temperature in the Arctic and the associated strong decline in sea ice. Both observational and climate modeling studies have shown that the Arctic is a region very susceptible to climate change; moreover, changes occurring in the Arctic are likely to have more wide-spread implications. Arctic amplification manifests itself in a number of ways, most notably in the current retreat and thinning of Arctic sea ice. A variety of processes and feedbacks have been proposed that contribute to amplified Arctic warming, most of them associated with sea ice. The most well-known is the surface-albedo feedback, which is associated with retreating sea-ice and snow cover. While most climate models exhibit an Arctic amplification signal with respect to ongoing and future changes, the inter-model range in simulated amplification is large, suggesting that the magnitudes of the various feedbacks contributing to Arctic warming and the role of sea ice therein are still uncertain. This session specifically aims to identify, characterize and quantify the processes and feedbacks that govern amplified Arctic warming and sea ice retreat, and it also addresses the climate impacts on the lower latitudes associated with Arctic changes (for instance the relation between sea ice reductions, heat flux changes and atmospheric circulation changes beyond the Arctic region). We therefore invite contributions on the causes, mechanisms and climate feedbacks associated with Arctic climate change and sea ice decline, and the possible links to weather and climate outside the Arctic. We welcome studies based both on climate model results and/or observational datasets, for near-past, present and future climate changes.

The Arctic Realm is changing rapidly and the fate of the cryosphere, including Arctic sea ice, glaciers and ice caps, is a source of concern. Whereas sea ice variations impact the radiative energy budget, thus playing a role in Arctic amplification, the Greenland Ice Sheet retreat contributes to global sea level rise. Moreover, through various processes linking the atmosphere, ice and ocean, the change in the Arctic realm may modify the atmospheric and ocean circulation at regional to global scales, the freshwater budget of the ocean and deep-water formation as well as the marine and terrestrial ecosystems, including productivity. The processes and feedbacks involved operate on all time scales and it require a range of types of information to understand the processes, drivers and feedbacks involved in Arctic changes, as well as the land-ocean-cryosphere interaction. In this session, we invite contributions from a range of disciplines and across time scales, including observational (satellite and instrumental) data, historical data, geological archives and proxy data, model simulations and forecasts, for the past, present and future climate. The common denominator of these studies will be their focus on a better understanding of mechanisms and feedbacks on short to long time scales that drive Arctic and subarctic changes and their impact on climate, ocean and environmental conditions, at regional to global scales, including possible links to weather and climate outside the Arctic.

The polar regions of the Arctic and Antarctica face a similar problem with most areas covered by ice and/or sea water. But both polar regions attract international attention due to the ongoing climate change. While the Arctic realm hosts vast extended continental shelves bordering old land masses, one of the largest submarine Large Igneous Provinces (LIPs) -the Alpha-Mendeleev Ridge - of Mesozoic age, and the slowest mid-ocean spreading ridge (the Gakkel Ridge) on the globe; West Antarctica has been, tectonically, the active margin between the cratonic East Antarctica and the Pacific Ocean for ~500 Ma, recording several episodes of magmatism, fragmentation and continental growth. Both regions have a complex geological history and comprise crustal blocks of disparate tectonic origins. In this regard, applied and theoretical research in sedimentology, tectonics, geophysics, and geochemistry to investigate the tectonic evolution and dynamics of the polar regions is desired. This session provides a forum for discussions of a variety of problems linked to the Circum-Arctic geodynamics as well as evolution of West Antarctica, and aims to bring together a diversity of sub-disciplines including plate tectonics, mantle tomography, seismology, geodynamic modelling, igneous and structural geology, geophysical imaging, sedimentology, and geochemistry.

The rapid decline of the Arctic sea ice in the last decade is a dramatic indicator of climate change. The Arctic sea ice cover is now thinner, weaker and drifts faster. Freak heatwaves are common. On land, the permafrost is dramatically thawing, glaciers are disappearing, and forest fires are raging. The ocean is also changing: the volume of freshwater stored in the Arctic has increased as have the inputs of coastal runoff from Siberia and Greenland and the exchanges with the Atlantic and Pacific Oceans. As the global surface temperature rises, the Arctic Ocean is speculated to become seasonally ice-free by the mid 21st century, which prompts us to revisit our perceptions of the Arctic system as a whole. What could the Arctic Ocean look like in the future? How are the present changes in the Arctic going to affect and be affected by the lower latitudes? What aspects of the changing Arctic should observational, remote sensing and modelling programmes address in priority?
In this session, we invite contributions from a variety of studies on the recent past, present and future Arctic. We encourage submissions examining interactions between the ocean, atmosphere and sea ice, on emerging mechanisms and feedbacks in the Arctic and on how the Arctic influences the global ocean. Submissions with a focus on emerging cryospheric, oceanic and biogeochemical processes and their implications are particularly welcome.
The session promotes results from current Arctic programmes and discussions on future plans for Arctic Ocean modelling and measurement strategies, and encourages submissions on the first results from CMIP6 and the recently completed Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC). This session is cosponsored by the CLIVAR /CliC Northern Ocean Regional Panel (NORP) that aims to facilitate progress and identify scientific opportunities in (sub)Arctic ocean-sea-ice-atmosphere research.

The North Atlantic exhibits a high level of natural variability from interannual to centennial time scales, making it difficult to extract trends from observational time series. Climate models, however, predict major changes in this region, which in turn will influence sea level and climate, especially in western Europe and North America. In the last years, several projects have been focused on the Atlantic circulation changes, for instance OVIDE, RACE, OSNAP, and ACSIS. Another important issue is the interaction between the atmosphere and the ocean as well as the cryosphere with the ocean, and how this affects the climate.

Please note that while we hope to hold a session in the traditional format, we anticipate that some part or all of the session may be held online.

We welcome contributions from observers and modelers on the following topics:

-- climate relevant processes in the North Atlantic region in the atmosphere, ocean, and cryosphere
-- response of the atmosphere to changes in the North Atlantic
-- atmosphere - ocean coupling in the North Atlantic realm on time scales from years to centuries (observations, theory and coupled GCMs)
-- interpretation of observed variability in the atmosphere and the ocean in the North Atlantic sector
-- Comparison of observed and simulated climate variability in the North Atlantic sector and Europe
-- Dynamics of the Atlantic meridional overturning circulation
-- variability in the ocean and the atmosphere in the North Atlantic sector on a broad range of time scales
-- changes in adjacent seas related to changes in the North Atlantic
-- role of water mass transformation and circulation changes on anthropogenic carbon and other parameters
-- linkage between the observational records and proxies from the recent past

Central and South America, including regions with complex topography such as the Andes, are subject to high impact weather events associated with interactions between multiple hydroclimatic and orographic factors, but also anthropic activities. These interactions lead to phenomena such as mesoscale convective events and cold air intrusions, which cause extreme precipitation events and impacts on the ground such as floods, landslides, and frosts. On the other hand, the region is also affected by the occurrence of heat waves and droughts and its related impacts. Moreover, Central and South America are among the regions with highest vulnerability to climate variability and change and land use change, with largely populated areas and biodiversity hotspots that are host to fragile human communities and ecosystems. During recent years, the scientific community has achieved important advances in understanding high impact weather events in the region. This session focuses on these advances and on the main scientific challenges to improve the understanding, simulation and forecasting of high impact weather events in the Andes and surrounding regions such as the Amazon, La Plata basin, Central America and the Caribbean. We welcome submissions focusing on high-impact events using observational, paleoclimate and modeling approaches. Studies based on the analysis of future projections under climate change and land use change scenarios are also welcome.

In recent years the interaction between the ocean and the cryosphere in the Southern Ocean has become a major focus in climate research. Antarctic climate change has captured public attention, which has spawned a number of research questions, such as: Is Antarctic sea ice becoming more vulnerable in a changing climate? What controls the inflow of warm water into ice shelf cavities and what is the impact of enhanced meltwater outflow? What role do ice processes play in nutrient upwelling on the shelf? Recent advances in observational technology, data coverage, and modeling provide scientists with a better understanding of the mechanisms involving ice-ocean interactions in the far South. Processes on the Antarctic continental shelf have been identified as missing links between the cryosphere, the global atmosphere and the deep open ocean that need to be captured in large-scale and global model simulations.

This session calls for studies on physical and biogeochemical interactions between ice shelves, sea ice and the ocean. The ice-covered Southern Ocean and its role in the greater Antarctic climate system are of major interest. This includes work on all scales, from local to basin-scale to circumpolar. Studies based on in-situ observations and remote sensing as well as regional to global models are welcome. We particularly invite cross-disciplinary topics involving physical and biological oceanography, glaciology or biogeochemistry.

Volcanoes release gas effluents and aerosol particles into the atmosphere during eruptive episodes and by quiescent emissions. Volcanic degassing exerts a dominant role in forcing the timing and nature of volcanic unrest and eruptions. Understanding the exsolution processes of gas species dissolved in magma, and measuring their emissions is crucial to characterise eruptive mechanism and evaluate the sub-sequent impacts on the atmospheric composition, the environment and the biosphere. Emissions range from silent exhalation through soils to astonishing eruptive clouds that release gas and particles into the atmosphere, potentially exerting a strong impact on the Earth’s radiation budget and climate over a range of temporal and spatial scales. Strong explosive volcanic eruptions are a major natural driver of climate variability at interannual to multidecadal time scales. Quiescent passive degassing and smaller-magnitude eruptions on the other hand can impact on regional climate system. Through direct exposure and indirect effects, volcanic emissions may influence local-to-regional air quality and seriously affect the biosphere and environment. Volcanic gases can also present significant hazards to populations downwind of an eruption, in terms of human, animal and plant health, which subsequently can affect livelihoods and cause socio-economic challenges. Gas emissions are measured and monitored via a range of in-situ and remote sensing techniques, to gain insights into both the subterranean-surface processes and quantify the extent of their impacts. In addition, modelling of the subsurface and atmospheric/climatic processes, as well as laboratory experiments, are fundamental to the interpretation of field-based and satellite observations.

This session focuses on the state-of-the-art and interdisciplinary science concerning all aspects of volcanic degassing and impacts of relevance to the Volcanology, Environmental, Atmospheric and Climate sciences (including regional climate), and Hazard assessment. We invite contributions on all aspects of volcanic plumes science, their observation, modelling and impacts. We welcome contributions that address issues around the assessment of hazards and impacts from volcanic degassing both in crises and at persistently degassing volcanoes.

Fire is an essential Earth system process that is rapidly changing in response to climate and human land use changes. Climate, vegetation and human activity regulate fire occurrence and spread, but fires also feedback to them in multiple ways. This session welcomes contributions on all aspects of linkages between fire, vegetation, climate, and humans to share recent advances and foster interdisciplinary discussions. We encourage all abstracts that explore the role of fire in the Earth system at any temporal and spatial scale using modeling, field and laboratory observations, and/or remote sensing, with an emphasis on studies that advance our understanding on interactions between fire and (1) weather, climate, and atmospheric chemistry, (2) biogeochemical cycles, land water and energy budgets, and vegetation composition and structure, and (3) human land management (e.g. impact of fire on air and water quality, deforestation, human health, and economy). We also welcome contributions focusing on fire characterization, including (4) fire behavior and emissions (e.g. fire duration, intensity, emission factors, emission height, smoke transport), (5) spatial and temporal changes of fires in the past, present, and future, (6) fire products and models, and their validation and error/bias assessment, and (7) analytical tools designed to enhance situational awareness among fire practitioners and early warning systems.

Observations and model simulations illustrate significant ocean variability and associated air-sea interactions in the tropical Atlantic basin from daily-to-decadal time scales. This session is devoted to the understanding of ocean dynamics in the tropical and subtropical Atlantic Ocean, its interaction with the overlying atmosphere from the equator to the mid-latitudes and its climate impacts on adjacent to remote areas.
Relevant processes in the ocean include upper and deep ocean circulation, eddies, tropical instability waves, warm pools, cold tongues and eastern boundary upwellings. We are interested in air-sea interactions related to both the seasonal cycle and the development of modes of variability from local to basin scale (e.g. the Meridional Mode, the Atlantic Niño, and the Benguela Niño). We welcome studies on wind variations related to the development of these modes, as well as studies on high-frequency events, such as marine heat waves, the Madden-Julian Oscillation, tropical cyclones and convective systems. Furthermore, we seek studies on climate change in the region, and also of the climatic impacts of change and variability on marine ecosystems. Finally, we are also interested in contributions examining the causes and impacts of systematic model errors in simulating the local to regional Atlantic climate.
Studies based on direct observations, reanalysis, reconstructions as well as model simulations are welcome.

The Andean Cordillera is cryospherically diverse, with high mountain glaciation in the north and large temperate ice masses in the south. These ice masses are critical for water security, the prevalence of geohazards, and a potentially substantial contribution to global sea level. The climatic influences on these ice masses vary across the Cordillera, and are strongly affected by large scale ocean-atmospheric systems such as ENSO and the Southern Annular Mode.

South America is one of the few landmasses in the ocean-dominated Southern Hemisphere available for terrestrial environmental and climate reconstructions. Palaeoclimatic records suggest that Patagonia was sensitive to the Antarctic Cold Reversal and variations in the Southern Annular Mode, which drives changes in the Southern Westerly Winds. Changes in these winds affect both Patagonia and Antarctica today. Further north, the glaciers in Peru and Bolivia are receding rapidly, threatening water security in these latitudes. These glaciers are strongly affected by rising atmospheric air temperatures and changes in ENSO. The high climate sensitivity of these glaciers and icefields, as well as their large latitudinal transect across the Andes, renders them a useful barometer of changes in large-scale atmospheric circulation and palaeoclimate.

We invite interdisciplinary contributions that investigate climate and cryosphere interactions over a range of timescale. This session will bring together researchers working on contemporary mass balance and climatology in the Andean Cordillera, Quaternary palaeoclimatic reconstructions from proxy data (including from lakes, bogs, marine records, aeolian records, ice cores, etc.), (palaeo)climate modelling, and reconstructions of former, present and future ice extent and dynamics from field-based studies and numerical modelling. It will provide a forum in which researchers can contrast their data and shed light on Quaternary glaciations and their palaeoclimatic drivers in South America. We especially invite studies that use data-model comparisons to improve projections of future climate and ice mass behaviour in the Andean Cordillera.

Land–atmosphere interactions often play a decisive role in shaping climate extremes. As climate change continues to exacerbate the occurrence of extreme events, a key challenge is to unravel how land states regulate the occurrence of droughts, heatwaves, intense precipitation and other extreme events. This session focuses on how natural and managed land surface conditions (e.g., soil moisture, soil temperature, vegetation state, surface albedo, snow or frozen soil) interact with other components of the climate system – via water, heat and carbon exchanges – and how these interactions affect the state and evolution of the atmospheric boundary layer. Moreover, emphasis is placed on the role of these interactions in alleviating or aggravating the occurrence and impacts of extreme events. We welcome studies using field measurements, remote sensing observations, theory and modelling to analyse this interplay under past, present and/or future climates and at scales ranging from local to global but with emphasis on larger scales.

The radiation budget of the Earth is a key determinant for the genesis and evolution of climate on our planet and provides the primary energy source for life. Anthropogenic interference with climate occurs first of all through a perturbation of the Earth radiation balance. We invite observational and modelling papers on all aspects of radiation in the climate system. A specific aim of this session is to bring together newly available information on the spatial and temporal variation of radiative and energy fluxes at the surface, within the atmosphere and at the top of atmosphere. This information may be obtained from direct measurements, satellite-derived products, climate modelling as well as process studies. Scales considered may range from local radiation and energy balance studies to continental and global scales. In addition, related studies on the spatial and temporal variation of cloud properties, albedo, water vapour and aerosols, which are essential for our understanding of radiative forcings, feedbacks, and related climate change, are encouraged. Studies focusing on the impact of radiative forcings on the various components of the climate system, such as on the hydrological cycle, on the cryosphere or on the biosphere and related carbon cycle, are also much appreciated.

Solicted speaker: Richard Allan

The large-scale atmospheric circulation strongly influences Earth's climate, both locally and globally, via its transport of energy, moisture, and momentum. While our ability to simulate the global circulation is improving, large model biases and uncertainties in climate change projections persist. Our theoretical understanding of how atmospheric circulations respond to climate changes is also limited, particularly on regional scales and in the presence of zonal asymmetries. Advancing our knowledge of the underlying dynamics is therefore crucial for reliable climate projections and for correctly interpreting palaeoclimate records.

The objective of this session is to advance our mechanistic understanding of atmospheric circulation changes and to analyse their impacts at global and regional scales, specifically on precipitation in past, present, and future climates. We encourage theoretical, observational and modelling contributions on tropical (ITCZ, monsoons, Hadley & Walker circulations, MJO) and extratropical circulations (jet streams, storm tracks, blocking).

Snow cover characteristics (e.g. spatial distribution, surface and internal physical properties) are continuously evolving over a wide range of scales due to meteorological conditions, such as precipitation, wind and radiation.
Most processes occurring in the snow cover depend on the vertical and horizontal distribution of its physical properties, which are primarily controlled by the microstructure of snow (e.g. density, specific surface area). In turn, snow metamorphism changes the microstructure, leading to feedback loops that affect the snow cover on coarser scales. This can have far-reaching implications for a wide range of applications, including snow hydrology, weather forecasting, climate modelling, and avalanche hazard forecasting or remote sensing of snow. The characterization of snow thus demands synergetic investigations of the hierarchy of processes across the scales ranging from explicit microstructure-based studies to sub-grid parameterizations for unresolved processes in large-scale phenomena (e.g. albedo, drifting snow).

This session is therefore devoted to modelling and measuring snow processes across scales. The aim is to gather researchers from various disciplines to share their expertise on snow processes in seasonal and perennial snowpacks. We invite contributions ranging from “small” scales, as encountered in microstructure studies, over “intermediate” scales typically relevant for 1D snowpack models, up to “coarse” scales, that typically emerge for spatially distributed modelling over mountainous or polar snow- and ice-covered terrain. Specifically, we welcome contributions reporting results from field, laboratory and numerical studies of the physical and chemical evolution of snowpacks, statistical or dynamic downscaling methods of atmospheric driving data, assimilation of in-situ and remotely sensed observations, representation of sub-grid processes in coarse-scale models, and evaluation of model performance and associated uncertainties.

NEMO (Nucleus for European Modelling of the Ocean) is a state-of-the-art modelling framework of the ocean that includes components for the ocean dynamics, the sea-ice and the biogeochemistry, so as a nesting package allowing to set up zooms and a versatile data assimilation interface (see https://www.nemo-ocean.eu/).
NEMO is used by a large community in Europe and world-wide (~200 projects, ~100 publications each year) covering a wide range of applications : oceanographic research, operational oceanography, seasonal forecast and climate projections.
NEMO is in particular used in 6 Earth System Models within CMIP6 and in Copernicus Marine Services (CMEMS) model-based products.

This session will provide a forum to properly address the new scientific advances in numerical modelling of the ocean and their implication for NEMO developments associated with:
• Ocean dynamics at large to coastal scales, up to 1km resolution ;
• Ocean biogeochemistry
• Sea-ice
• New numerical schemes associated to energy conservation constraints
• High performance computing challenges and techniques

The session will cover both research and operationnal activities contributing to new analysis, ideas and developments of ocean numerical models.
Presentations of results based on new NEMO functionalities and new NEMO model configurations are welcome.

Several subsystems of the Earth system have been suggested to react abruptly at critical levels of anthropogenic forcing. Well-known examples of such Tipping Elements include the Atlantic Meridional Overturning Circulation, the polar ice sheets and sea ice, tropical and boreal forests, as well as the Asian monsoon systems. Interactions between the different Tipping Elements may either have stabilizing or destabilizing effects on the other subsystems, potentially leading to cascades of abrupt transitions. The critical forcing levels at which abrupt transitions occur have recently been associated with Tipping Points.

It is paramount to determine the critical forcing levels (and the associated uncertainties) beyond which the systems in question will abruptly change their state, with potentially devastating climatic, ecological, and societal impacts. For this purpose, we need to substantially enhance our understanding of the dynamics of the Tipping Elements and their interactions, on the basis of paleoclimatic evidence, present-day observations, and models spanning the entire hierarchy of complexity. Moreover, to be able to mitigate - or prepare for - potential future transitions, early warning signals have to be identified and monitored in both observations and models.

This multidisciplinary session invites contributions that address Tipping Points in the Earth system from the different perspectives of all relevant disciplines, including

- the mathematical theory of abrupt transitions in (random) dynamical systems,
- paleoclimatic studies of past abrupt transitions,
- data-driven and process-based modelling of past and future transitions,
- early-warning signals
- the implications of abrupt transitions for Climate sensitivity and response,
- ecological and societal impacts, as well as
- decision theory in the presence of uncertain Tipping Point estimates

Significant advances in our understanding of the Meso- and Cenozoic development of polar regions have been made over the last two decades by studying continental shelf, slope, or deep-sea sediment sequences. These include detailed reconstructions of the climatic, oceanographic, and tectonic evolution of high northern and southern latitudes over various time scales, as well as reconstructions of past ice-sheet dynamics and studies of marine geohazards. Data have been obtained from conventional and high-resolution 2D and 3D seismic surveying, from a growing number of short sediment cores, and from targeted high-latitude deep drilling expeditions (e.g. IODP, MeBo). The same techniques have also been applied in fjords, which link the continental margins with the interiors of landmasses and act as “miniature ocean basins”. Fjord settings allow us to study similar geological processes to those that acted on glaciated continental margins but at smaller scales. The variety of sediment inputs (e.g. glacial, fluvioglacial, fluvial, biological) to fjord basins along with relatively high sedimentation rates provides the potential for high-resolution palaeoclimatic and palaeooceanographic records on decadal to centennial timescales.

The aim of this session is to bring together researchers working on both northern and southern high latitudes processes spanning various spatio-temporal scales from fjords to the deep sea, to provide a multi-disciplinary picture of polar regions. We welcome submissions focussing on (but not limited to) records of past climatic change, tectonics, oceanography and ecosystems, and the associated links with ice sheets and glacier behaviour, ice-ocean interactions and glacial-marine sedimentary processes. Studies that integrate different datasets, data types, or that marry observations with numerical modelling are also encouraged.

We dedicate this session to our dear colleague and co-convener, Christian Hass, whose enthusiasm and knowledge helped shape this session over many years.

Recent years have seen a substantial progress in the understanding of the nonlinear and stochastic processes responsible for important dynamical aspects of the complex Earth system. The Earth system is a complex system with a multitude of spatial and temporal scales which interact nonlinearly with each other. For understanding this complex system new methods from dynamical systems, complex systems theory, complex network theory, statistics, machine learning and climate and Earth sciences are needed.

In this context the session is open to contributions on all aspects of the nonlinear and stochastic dynamics of the Earth system, including the atmosphere, the ocean and the climate system. Communications based on theoretical and modeling studies, as well as on experimental investigations are welcome. Studies that span the range of model hierarchy from idealized models to complex Earth System Models (ESM), data driven models, use observational data and also theoretical studies are particularly encouraged.

The interactions between aerosols, climate, and weather are among the large uncertainties of current atmospheric research. Mineral dust is an important natural source of aerosol with significant implications on radiation, cloud microphysics, atmospheric chemistry and the carbon cycle via the fertilization of marine and terrestrial ecosystems.

In addition, properties of dust deposited in sediments and ice cores are important (paleo-)climate indicators.

This interdivision session --building bridges between the EGU divisions CL, AS, SSP, BG and GM-- is open to contributions dealing with:

(1) measurements of all aspects of the dust cycle (emission, transport, deposition, size distribution, particle characteristics) with in situ and remote sensing techniques,

(2) numerical simulations of dust on global and regional scales,

(3) meteorological conditions for dust storms, dust transport and deposition,

(4) interactions of dust with clouds and radiation,

(5) influence of dust on atmospheric chemistry,

(6) fertilization of ecosystems through dust deposition,

(7) any study using dust as a (paleo-)climate indicator including sediment archives in loess, ice cores, lake sediments, ocean sediments and dunes.

We especially encourage to submit papers on the integration of different disciplines and/or modelling of past, present and future climates.

In 2021 we look forward to hear three solicited speakers present their latest work.

We are proud to announce:

1) Siyu Chen, professor at Lanzhou University, China.
Siyu will present her work on modelling emission, transport and radiative effects of Asian mineral dust

2) Kevin Ohneiser, PhD student at TROPOS, Leipzig, Germany

Kevin will present his latest findings on aerosols observed during the MOSAIC campaign

3) Jeff Munroe, professor at Middlebury College, USA

Jeff will present his latest findings from the DUST^2 project; a source-to-sink investigation of the modern dust system in SW North America

Share: https://meetingorganizer.copernicus.org/EGU21/session/40684

Volcanic aerosol clouds from major tropical eruptions cause periods of strong surface cooling in the historical climate record and are dominant influences within decadal surface temperature trends.

Even the transition from the unusual 1998-2002 period of a “fully decayed to quiescence” stratospheric aerosol layer, into a more typical period of modest volcanic activity temporarily offset a substantial proportion of the subsequent decadal forcing from increased greenhouse gases.

Advancing our understanding of the influence of volcanoes on climate relies upon better knowledge of (i) the radiative forcings of past eruptions and the microphysical, chemical and dynamical processes which affect the evolution of stratospheric aerosol properties and (ii) the response mechanisms governing post-eruption climate variability and their dependency on the climate state at the time of the eruption. This can only be achieved by combining information from satellite and in-situ observations of recent eruptions, stratospheric aerosol and climate modelling activities, and reconstructions of past volcanic histories and post-eruption climate state from proxies.

In recent years the smoke from intense wildfires in North America and Australia has also been an important component of the stratospheric aerosol layer, the presence of organic aerosol and meteoric particles in background conditions now also firmly established.

This session seeks presentations from research aimed at better understanding the stratospheric aerosol layer, its volcanic perturbations and the associated impacts on climate through the post-industrial period (1750-present) and also those further back in the historical record.

We also welcome contributions to understand the societal impacts of volcanic eruptions and the human responses to them. Contributions addressing volcanic influences on atmospheric composition, such as changes in stratospheric water vapour, ozone and other trace gases are also encouraged.

The session aims to bring together research contributing to several current international co-ordinated activities: SPARC-SSiRC, CMIP6-VolMIP, CMIP6-PMIP, and PAGES-VICS.

Adapting to climate change in the Mediterranean region represents a critical socio-economic and environmental challenge. Different levels of exposure and vulnerability as well as different projected changes characterize the Mediterranean region. Understanding the past, characterizing the present and modelling the future are therefore essential steps to estimate the risks, assess the impacts of climate change, and identify potential adaptation and mitigation strategies. This multidisciplinary MedCLIVAR session encourages contributions from a broad range of disciplines and topics, e.g. dealing with: dynamics and processes of the climate system; sectorial impacts of climate change; climate change adaptation and mitigation; innovative methods and approaches in climate science. The session focuses on all time scales from paleoclimate to future model projections as well as on all relevant socio-economic sectors.

The Arctic sea ice and high latitude atmosphere and oceans have experienced significant changes over the modern observational era. The polar climate is crucial for the Earth’s energy and water budget, and its variability and change have direct socio-economic and ecological impacts. Thus, understanding high-latitude variability and improving predictions of high latitude climate is highly important for society. Long-term variability in ocean and sea ice are the largest sources for predictability in high latitudes. Dynamical model predictions are not yet in the position to provide us with highly accurate predictions of the polar climate. Main reasons for this are the lack of observations in high latitudes, insufficient initialization methods and shortcomings of climate models in representing some of the important climate processes in high latitudes.

This session aims for a better understanding and better representation of the mechanisms that control high latitude variability and predictability of climate in both hemispheres from sub-seasonal to multi-decadal time-scales in past, recent and future climates. Further, the session aims to discuss ongoing efforts to improve climate predictions at high latitudes at various time scales (as e.g. usage of additional observations for initialization, improved initialization methods, impact of higher resolution, improved parameterizations, novel verification approaches) and potential teleconnections of high latitude climate with lower latitude climate. We also aim to link polar climate variability and predictions to potential ecological and socio-economic impacts and encourage submissions on this topic.

The session offers the possibility to present results from ongoing projects and research efforts on the topic of high-latitude climate variability and prediction, including, but not limited to, the WMO Year of Polar Prediction (YOPP), NordForsk-project ARCPATH, MOSAiC, and the H2020-projects APPLICATE, INTAROS, BlueAction, and KEPLER.

The Indian Ocean is unique among the other tropical ocean basins due to the seasonal reversal of monsoon winds and concurrent ocean currents, lack of steady easterlies that result in a relatively deep thermocline along the equator, low-latitude connection to the neighboring Pacific and a lack of northward heat export due to the Asian continent. These characteristics shape the Indian Ocean’s air-sea interactions, as well as its variability on (intra)seasonal, interannual, and decadal timescales. They also make the basin and its surrounding regions, which are home to a third of the global population, particularly vulnerable to anthropogenic climate change: robust trends in heat transport and freshwater fluxes have been observed in recent decades in the Indian Ocean and Maritime Continent region and 2019 marked one of the largest Indian Ocean Dipole events on record. Advances have recently been made in our understanding of the Indian Ocean’s circulation, interactions with adjacent ocean basins, and its role in regional and global climate. Nonetheless, significant gaps remain in understanding, observing, modeling, and predicting Indian Ocean variability and change across a range of timescales.
This session invites contributions based on observations, modelling, theory, and palaeo proxy reconstructions in the Indian Ocean that focus on recent and projected changes in Indian Ocean physical and biogeochemical properties and their impacts on ecological processes, interactions and exchanges between the Indian Ocean and other ocean basins, as well as links between Indian Ocean variability and monsoon systems across a range of timescales. In view of the large 2019 event, contributions on the Indian Ocean Dipole mechanisms and climate impacts, with a particular focus on extreme events, are particularly sought. We also welcome contributions that address research on the Indian Ocean grand challenges highlighted in the recent IndOOS Decadal Review, and as formulated by the Climate and Ocean: Variability, Predictability, and Change (CLIVAR), the Sustained Indian Ocean Biogeochemistry and Ecosystem Research (SIBER), the International Indian Ocean Expedition 2 (IIOE-2), and the Year of the Maritime Continent (YMC) programs.

Connectivity with the ocean and climate strongly control the physical and chemical properties of restricted marine basins, sometimes leading to the formation of large evaporite accumulations known as salt giants. As a result of these processes, salinity, water oxygenation and nutrient availability may develop trends distinct from those of the global ocean, resulting in extreme salinity – from brackish to evaporitic – and driving ecosystems through specific patterns of origination and extinction. Reversely, the genesis and demise of such physico-chemically distinct water bodies changes global ocean circulation patterns, affects climate and leads to shifts in the location of global biodiversity hotspots. Our session mostly includes presentations on the Mediterranean, the Dead Sea, using modelling, sesimic stratigraphic, (bio)geochemical, sedimentologic and micropaleontological methods to investigate feedbacks between hydroclimate, tectonics and marine biota.

At the 2015 Paris COP21 climate conference, 195 countries committed to reduce their greenhouse gas emissions and make efforts to significantly limit man-made global warming to below 2°C above pre-industrial levels. France and Germany joined forces in this fight against global warming by creating the “Make Our Planet Great Again” research initiative covering research in Earth system science that aims to better understand climate change and its impacts on natural and socio-economic systems. In this interdisciplinary session, we welcome data- and model-based research undertaken within, but also outside this international initiative. We welcome contributions that provide new insights into the mechanisms of past, present and future climate changes and the associated impacts on the oceans, the cryosphere, coastal regions, and terrestrial systems. Innovative research contributions that can lead towards the ultimate goals of the Paris Agreement ranging from basic research to solution-oriented research are also encouraged.

Abstracts are solicited related to the understanding and prediction of weather, climate and geophysical extremes, from both an applied sciences and theoretical viewpoint.

In this session we propose to group together the traditional geophysical sciences and more mathematical/statistical approaches to the study of extremes. We aim to highlight the complementary nature of these two viewpoints, with the aim of gaining a deeper understanding of extreme events.

Potential topics of interest include but are not limited to the following:

· How extremes have varied or are likely to vary under climate change;
· How well climate models capture extreme events;
· Attribution of extreme events;
· Emergent constraints on extremes;
· Linking dynamical systems extremes to geophysical extremes;
· Extremes in dynamical systems;
· Downscaling of weather and climate extremes.
· Linking the dynamics of climate extremes to their impacts

The Earth's climate is highly variable on all spatial and temporal scales, and this has direct consequences for society. For example, changes in variability (spatial or temporal) can impact the recurrence frequency of extreme events. Yet it is unclear if a warmer future is one with more or with less climate variability, and at which scales, as a multitude of feedbacks is involved and the instrumental record is short.
We welcome contributions that improve quantification, understanding, and prediction of climate variability in the Earth system across space and timescales through case studies, idealized or realistic modeling, synthesis, and model-data comparison studies that provide insights into past, present and future climate variability on local to global, and synoptic to orbital timescales.

The session is multidisciplinary and brings together people working in the geosciences, atmospheric science, oceanography, glaciology, paleoclimatology and environmental physics, to examine the complementarity of ideas and approaches. Members of the PAGES working group on Climate Variability Across Scales (CVAS) and others are welcome.

This session aims to provide a forum to present work on:

1- the characterization of climate dynamics using a variety of techniques (e.g. scaling and multifractal techniques and models, recurrence plots, or variance analyses) to study its variability including periodicities, noise levels, or intermittency)

2- the relationship between changes in the mean state (e.g. glacial to interglacial or preindustrial to present to future), and higher-order moments of relevant climate variables, to changes in extreme-event occurrence and the predictability of climate

3- the role of ocean, atmosphere, cryosphere, and land-surface processes in fostering long-term climate variability through linear – or nonlinear – feedbacks and mechanisms

4- the attribution of climate variability to internal dynamics, or the response to natural (volcanic or solar) and anthropogenic forcing

5- the interaction of external forcing (e.g. orbital forcing) and internal variability such as mechanisms for synchronization and pacing of glacial cycles

6- the characterization of probabilities of extremes, including linkage between slow climate variability and extreme event recurrence

The Earth’s subsurface hosts enormous methane volumes either trapped in the shallow sediments, gas hydrates and permafrost, or naturally escaping the sediment through methane seepage to enter the hydrosphere/atmosphere. Such environments are highly sensitive to climate change. Despite an increasing awareness about the positive feedback between global warming and methane seepage, the response of these complex and dynamic systems to climate change is still unclear due to complex geo/hydro/atmosphere interactions.
Fossil cold seeps, long-term observatory studies and modern examples form the foundations to understand the mutual dependences between climate and seepage, and to develop robust models to forecast future scenarios at the Earth-system scale. For this session, we welcome geologists, geophysicists, geochemists, biologists, model developers, and any others who have contributed to new case studies in modern and fossil hydrocarbon seeps in the marine and terrestrial environment, gas hydrate and permafrost settings, to describe both new methods/technologies and the scientific outcomes.

Over recent decades we have gained a robust understanding of climate change fundamentals, but its specific and localized impacts are anything but certain. The need to provide boundary conditions for forecasting and computational modelling has increased the importance of quantitative methods in the field of palaeoenvironmental, palaeoclimatic and palaeohydrological reconstruction.

Continental environmental archives (e.g. speleothems, lake and river sediments, peatlands, and vertebrate and invertebrate remains) are often highly temporally resolved (subdecadal to seasonal) and provide more direct information about atmospheric and hydrological processes than marine archives. The wide variety of continental archives allows for intercomparison and ground-truthing of results from different environments, while multi-proxy reconstructions from the same archive can disentangle local and supra-regional environmental conditions. This approach is particularly useful when dealing with high spatial variability, signal buffering, nonlinearities, and uncertainties in the proxy sensitivity.

This session aims to highlight recent advances in the use of innovative and quantitative proxies to reconstruct past environmental change on land. We welcome studies of all continental archives, including but not limited to carbonates (caves, palaeosols, snails), sediments (lakes, peatlands, rivers, alluvial fans), and biological materials (tree rings, fossil assemblages, bones, biomarkers). We particularly encourage studies involving the calibration of physical and chemical proxies that incorporate modern transfer functions, forward modeling and/or geochemical modeling to predict proxy signals, and quantitative estimates of past temperature and palaeohydrological dynamics. We also invite reconstructions of temperature and hydrologic variability over large spatial scales and palaeoclimate data assimilation. This session provides a forum for discussing recent innovations and future directions in the development of continental palaeoenvironmental proxies on seasonal to multi-millennial timescales.

The importance of radiocarbon (14C) as an environmental tracer has been increasingly recognized in recent years. 14C is a key tool in the scientific effort for gaining insights into the global carbon cycle, with diverse studies using 14C to investigate the carbon held in the biosphere and atmosphere, dissolved in the oceans, and sequestered in the geosphere, as well as the transfers between these reservoirs. 14C is a valuable tracer of ocean circulation and anthropogenic activities on the atmosphere. Analytical tools have matured over the last decades, including downscaling the sample size (< 20 µg C) and increasing the sample throughput, helping to expand the range of 14C applications.
This session brings together an interdisciplinary group of researchers that advance and apply 14C analyses or use 14C data. It covers a variety of topics, including experimental and analytical advancements (e.g., sample preparation, increasing the sample throughput and decreasing sample size, broadening the range of compounds that can be isolated) and novel insights into the carbon cycle and associated processes using new measurements, data analysis or models (e.g., storage times in soils, sediment dispersal, ocean circulation, or carbon transfer between reservoirs).

The Quaternary Period (last 2.6 million years) is characterized by frequent and abrupt climate swings that were accompanied by rapid environmental change. Studying these changes requires accurate and precise dating methods that can be effectively applied to environmental archives. A range of different methods or a combination of various dating techniques can be used, depending on the archive, time range, and research question. Varve counting and dendrochronology allow for the construction of high-resolution chronologies, whereas radiometric methods (radiocarbon, cosmogenic in-situ, U-Th) and luminescence dating provide independent anchors for chronologies that span over longer timescales. We particularly welcome contributions that aim to (1) reduce, quantify and express dating uncertainties in any dating method, including high-resolution radiocarbon approaches; (2) use established geochronological methods to answer new questions; (3) use new methods to address longstanding issues, or; (4) combine different chronometric techniques for improved results, including the analysis of chronological datasets with novel methods, e.g. Bayesian age-depth modeling. Applications may aim to understand long-term landscape evolution, quantify rates of geomorphological processes, or provide chronologies for records of climate change.

Reliable information on past environmental and climatic conditions is crucial for understanding the evolution of life and the Earth System as a whole. Skeletal components of marine or aquatic organisms are among the most important and widely-used natural archives capturing information about the environment and fluid chemistry during precipitation in the form of geochemical signatures and/or specific mineralogies or micromorphologies. Over the past decades, a refined understanding of (bio)mineralisation, together with the development of new isotopic and elemental proxies (e.g. clumped isotopes Δ47, boron isotopes δ11B, or elemental ratios such as Li/Mg), has led to numerous breakthroughs in palaeoclimate research (e.g. on the evolution of seawater chemistry, causes and consequences of mass extinctions, or greenhouse vs. icehouse climate sensitivities). Simultaneously, geochemical, petrographic and crystallographic approaches have brought novel insights into (bio)mineral formation processes and alteration pathways of a variety of organisms. Critically, however, our knowledge of the incorporation of elements into the crystal lattice, and the quality and reliability of extracted climatic and environmental records, depends on careful proxy calibrations, and evaluation of secondary controls such as kinetic or vital effects and diagenetic influences.

This session seeks contributions on geochemical proxy development, including but not limited to new proxies, calibrations, modelling frameworks, and analytical or methodological advances. We invite experimental and observational studies dealing with biogenic but also inorganic mineral precipitation, transformation and alteration, including interface geochemistry, geomicrobiology or new perspectives on biomineralisation from culturing of calcifying organisms. We also welcome examples on how mechanistic understanding of marine or terrestrial carbonates and/or application of novel approaches results in an improved understanding of the global carbon(ate) cycle and Earth history. The aim of this session is to synthesize recent advances in geochemistry and (bio)mineralisation to further palaeo-proxy development and application that will result in a comprehensive understanding of past global changes.

Scientific ocean and continental drilling provides unique opportunities to investigate the workings of the interior of our planet, Earth’s cycles, natural hazards and the distribution of subsurface microbial life. The past and current scientific drilling programs IODP (International Ocean Discovery Program) and ICDP (International Continental Scientific Drilling Program) have brought major advances in many multidisciplinary fields of socio-economic relevance, such as climate and ecosystem evolution, palaeoceanography, the deep biosphere, deep crustal and tectonic processes, geodynamics and geohazards. This session encourages contributions that outline perspectives and visions for future drilling projects, in particular projects using a multi-platform approach, and invites contributions that present and/or review recent scientific results from deep Earth sampling and monitoring through ocean and continental drilling projects.
This year, a particular focus will be given on contributions based on sedimentary records from outcrops or the often more complete sedimentary sections recovered by scientific drilling that reconstruct sedimentary processes and their products preserved in deltas, canyons and submarine fans (former session SSP 2.9).

Solar Irradiance is the key energy input to Earth. A positive Earth Energy Imbalance (EEI) is the energy, which is continuously stored by the Earth and will ultimately be released to the atmosphere, causing global warming. In order to determine its exact value both the Total Solar Irradiance (TSI) and the Top of the Atmosphere (ToA) Outgoing Radiation (TOR) need to be measured with unprecedented accuracy and precision. However, so far, the EEI could not be determined as the measurements were not sufficiently accurate. This calls for improved instrument technologies as well as a traceable calibration chain of the space instrumentation. In this session we invite contributions on the both the measurement of solar irradiance as well as the Earth outgoing radiation which ultimately aim to pave the way to determine EEI from space.

This session intends to showcase climate related studies which have made use of geodetic observations and or techniques.
Modern geodetic observing systems are sensitive to a wide range of changes in the Earth’s solid and fluid layers at very diverging spatial and temporal scales related to processes as, e.g., glacial isostatic adjustment, the terrestrial water cycle, ocean dynamics, sea-level and ice-mass balance. Geodetic observables are often compared with geophysical models, which helps to explain observations, evaluate simulations, and may potentially be used to improve simulations through techniques such as data assimilation.

We invite contributions utilizing geodetic data from e.g. altimetry, gravimetry (CHAMP, GRACE, GOCE and GRACE-FO), navigation satellite systems (GNSS and DORIS) or remote sensing techniques that are based on both passive (e.g. optical and multi/hyperspectral) and active (i.e., SAR) instruments. New approaches helping to separate and interpret the variety of geophysical signals present in observations are equally appreciated.

The session closely adheres to the ideas of the recently established Inter-Commission Committee on "Geodesy for Climate Research" (ICCC) of the International Association of Geodesy (IAG), which aims to encourage collaborations between the climate and geodetic community and promote the use of geodetic observations and principles while at the same time benefiting from climate expertise in the interpretation and correction of geodetic observations. We encourage authors to tailor their presentations to include non-geodetic scientists as their audience, and, with the author’s consent, highlights from this session will be tweeted in order to increase visibility.

Modelling the Earth system with state-of-the-art Earth System models is computationally expensive. Therefore, simple climate models (SCMs, also known as “reduced complexity” models and “emulators”) are useful as they are able to produce individual climate projections with reduced computational resources. This low computational burden enables the generation of large model ensembles where climate response, carbon cycle and forcing parameters can be varied, and internal variability and teleconnections emulated, allowing for probabilistic projections of a range of climate features. Simple climate models may be physical or statistical in nature, and can range in complexity from spreadsheet-based projections of global-mean temperature from prescribed radiative forcing through to Earth System Models of Intermediate Complexity and reduced resolution variants of operational ESMs. SCMs have historically proven useful in translating knowledge of physical processes, the carbon cycle and other Earth System responses into a format useful for the economical and social sciences, and policy/decision makers.

We invite presentations on all aspects of the development and application of simple climate and geophysical models, including but not limited to:
1. the development of simple climate models and results
2. the role of simple climate models in integrated assessment and scenario generation
3. best practices in tuning and calibration of simple models to observations and complex Earth System models
4. strategies for emulating internal variability, regional climate and climate extremes
5. models that focus on one particular complex aspect of the Earth system (for example atmospheric chemistry, land and ocean carbon cycles, or the cryosphere)
6. uses of simple climate models in outreach and education

This session invites presentations on simulations of weather and climate models running at high resolution. This includes state-of-the-art storm-resolving simulations (e.g. from the DYAMAND project), high-resolution climate models (e.g. from the PRIMAVERA project) but also large-eddy simulations and high-resolution ocean modelling. Presentations can cover developments to improve model fidelity (e.g. via improved parametrisations), detailed studies of modelled phenomena (e.g. tropical cyclones) but also computational and model development challenges (e.g. the use of GPUs, domain-specific languages or the development of new dynamical cores).

In weather prediction and climate modelling, numerical models of the Earth System are used extensively. For both the atmosphere and ocean components such models consist of a fluid dynamics solver (dynamical core) coupled to physical parameterizations to represent processes that occur below the grid scale (physics). Over time these models have become capable of sophisticated simulations. Research and development is constantly being undertaken to improve the accuracy and efficiency of the dynamical core, the physics, and their coupling.

This session encompasses the development, testing and application of novel numerical techniques for Earth system models, including governing equations, horizontal and vertical discretizations, structure preserving methods, time stepping schemes, advection schemes, adaptive multi-scale models, physics-dynamics coupling, regional and global models, classical and stochastic physical parameterizations (that are not covered in other sessions).

The ‚user‘s dilemma‘ is known to be no longer the lack of downscaled data, it is how to choose an appropriate data set and how to assess its credibility. This session invites contributions that present and evaluate downscaling methods in the atmospheric sciences, including statistical downscaling, regional climate modeling, atmospheric models of intermediate complexity, as well as studies presenting impact assessments based on downscaling products. This year, we particularly encourage a discussion about uncertainty, the comparative performance amongst the different approaches, and their added value over the coarser-scale atmospheric driving data sets.

Accurate and homogeneous long-term data records (i.e., data that are forced to look like a common reference) are essential for researching, monitoring, or attenuating changes in climate, for example to describe the state of climate or to detect climate extremes. Likewise, reanalysis needs accurate and harmonized data records (i.e., data records in which the unique nature of each sensor is maintained). Temporal changes, such as degradation of instruments, changes of instruments, changes of observation practices, or changes of station location and exposure, cause artificial non-climatic sudden or gradual changes in data records. The magnitude and uncertainty of these changes impact the results of climate trend analyses. Therefore, data intended for applications, such as making a realistic and reliable assessment of historical climate trends and variability, require to be homogenized or harmonized consistently so as to obtain well calibrated data records including measurement uncertainties.

The above described factors influence the quality of different essential climate variables, including atmospheric (e.g., air temperature, precipitation, wind speed), oceanic (e.g., sea surface temperature), and terrestrial (e.g., albedo, snow cover) variables from in-situ observing networks, satellite observing systems, and climate/earth-system model simulations. Our session calls for contributions related to the:

• Calibration, quality control, homogenization/harmonisation and validation of either fundamental or essential climate data records.

• Development of new data records and their analysis (spatial and temporal characteristics, particularly of extremes).

• Examination of observed trends and variability, as well as studies that explore the applicability of techniques/algorithms to data of different temporal resolutions (annual, seasonal, monthly, daily, and sub-daily).

• Rescue and analysis of centennial meteorological observations, with focus on data prior to the 1960s, as a unique source to fill in the gap of knowledge of climate variability over century time-scales.

Statistical post-processing techniques for weather, climate, and hydrological forecasts are powerful approaches to compensate for effects of errors in model structure or initial conditions, and to calibrate inaccurately dispersed ensembles. These techniques are now an integral part of many forecasting suites and are used in many end-user applications such as wind energy production or flood warning systems. Many of these techniques are flourishing in the statistical, meteorological, climatological, hydrological, and engineering communities. The methods range in complexity from simple bias correction up to very sophisticated distribution-adjusting techniques that take into account correlations among the prognostic variables.

At the same time, a lot of efforts are put in combining multiple forecasting sources in order to get reliable and seamless forecasts on time ranges from minutes to weeks. Such blending techniques are currently developed in many meteorological centers.

In this session, we invite presentations dealing with both theoretical developments in statistical post-processing and evaluation of their performances in different practical applications oriented toward environmental predictions, and new developments dealing with the problem of combining or blending different types of forecasts in order to improve reliability from very short to long time scales.

There are many ways in which machine learning promises to provide insight into the Earth System, and this area of research is developing at a breathtaking pace.
Unsupervised, supervised as well as reinforcement learning are now increasingly used to address Earth system related challenges.
Machine learning could help extract information from numerous Earth System data, such as satellite observations, as well as improve model fidelity through novel parameterisations or speed-ups. This session invites submissions spanning modelling and observational approaches towards providing an overview of the state-of-the-art of the application of these novel methods

This interdisciplinary session welcomes contributions on novel conceptual and/or methodological approaches and methods for the analysis and statistical-dynamical modeling of observational as well as model time series from all geoscientific disciplines.
Methods to be discussed include, but are not limited to linear and nonlinear methods of time series analysis. time-frequency methods, statistical inference for nonlinear time series, including empirical inference of causal linkages from multivariate data, nonlinear statistical decomposition and related techniques for multivariate and spatio-temporal data, nonlinear correlation analysis and synchronisation, surrogate data techniques, filtering approaches and nonlinear methods of noise reduction, artificial intelligence and machine learning based analysis and prediction for univariate and multivariate time series.
Contributions on methodological developments and applications to problems across all geoscientific disciplines are equally encouraged. We particularly aim at fostering a transfer of new methodological data analysis and modeling concepts among different fields of the geosciences.

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Sub-Session "Mathematical Climatology and Space-time Data Analysis" (Abdel Hannachi, Amro Elfeki, Christian Franzke, Muhammad Latif, Carlos Pires)

The recent progress in mathematical methods to solve various problems in weather & climate nonlinear dynamics and data analysis calls for the need to develop a new session that focus on those methods. Novel and powerful mathematical methods have been developed and used in different subjects of climate. Because those methods are used within specific contexts they go unnoticed most of the time by climate researchers. The proposed new session will provide the opportunity to climate scientists and researchers working on developing mathematical methods for climate to come together and present their findings in a transparent way. This will also be easily accessible to other climate scientists who look for, and are interested in specific methods to solve their problems.
Contributions are encouraged from researchers working on mathematical methods and their application to weather and climate. We particularly welcome contributions on optimization, dimension reduction and data mining, space-time patterns identification, machine learning, statistical prediction modelling, nonlinear methods , Bayesian statistics, and Monte-Carlo Markov Chain (MCMC) methods in stochastic modelling.

Several single model large ensemble simulations from Global Climate Models (GCM), Earth System Models (ESM), or Regional Climate Models (RCM), have been generated over the recent years to investigate internal variability and forced changes of the climate system—and to aid the interpretation of the observational record by providing a range of historical climate trajectories that could have been. The increased availability of large ensembles also enables new and inter-disciplinary applications beyond large-scale climate dynamics.

This session invites studies using large GCM, ESM, or RCM ensembles looking at the following topics: 1) Reinterpretation of the observed record in light of internal variability; 2) forced changes in internal variability; 3) development of new approaches to attribute observed events or trends; 4) impacts of natural climate variability; 5) assessment of extreme and compound event occurrence; 6) combining single model large ensembles with CMIP archives for robust decision making; 7) large ensembles as testbeds for method development.

We welcome research across all components of the Earth system, including for example hydrology and biogeochemistry, but also research on the role of internal variability in impact studies focused for example on agriculture, air pollution or energy generation and consumption. We particularly invite studies that apply novel methods or cross-disciplinary approaches to leverage the potential of large ensembles.

Lagrangian trajectories are currently used for a vast range of purposes in ocean and atmosphere sciences. Examples include studying the connectivity of ocean basins, forecasting the spreading of ash clouds, mapping global ocean diffusivities, observing the deep ocean, or tracing plastics and other forms of pollutants in the ocean, etc. There is thus a need for numerical models capable of simulating Lagrangian particles in the ocean and atmosphere as well as accurate methods for analysing the data from surface drifters, floats, and simulated particles.

This session aims at bringing together scientists working on all sorts of Lagrangian methods, e.g. observed or simulated particles in the atmosphere and ocean, and a variety of use cases e.g. studying oceanic mixing/diffusivity, tracing pollution in the atmosphere or ocean, iceberg tracking etc. We welcome presentations on e.g.:

* Connectivity and pathways of air- or water-masses in the atmosphere and the ocean
* Quantifying water mass transformations and fluxes between regions in the ocean
* Development of Lagrangian particle-tracking algorithms and approaches to model particles with active behaviours, e.g. icebergs, fish, ash clouds, plastics etc.
* New methods and tools to analyse observed or simulated Lagrangian particles, e.g. diffusivity, spreading rates, etc.
* New developments in in-situ observations such as balloons, surface drifters or floats.

After the PhD, a new challenge begins: finding a position where you can continue your research or a job outside academia where you can apply your advanced skills. This task is not always easy, and frequently a general overview of the available positions is missing. Furthermore, in some divisions, up to 70% of PhD graduates will go into work outside of academia. There are many different careers which require or benefit from a research background. But often, students and early career scientists struggle to make the transition due to reduced support and networking.
In this panel discussion, scientists with a range of backgrounds give their advice on where to find jobs, how to transition between academia and industry and what are the pros and cons of a career inside and outside of academia.
In the final section of the short course, a Q+A will provide the audience with a chance to ask their questions to the panel. This panel discussion is aimed at early career scientists but anyone with an interest in a change of career will find it useful. An extension of this short course will run in the networking and early career scientist lounge, for further in-depth or one-on-one questions with panel members.

Most often observations and measurements of geophysical systems and dynamical phenomena are obtained as time series whose dynamics usually manifests a nonlinear behavior. During the past decades, nonlinear approaches in geosciences have rapidly developed to gain novel insights on fluid dynamics, greatly improving weather forecasting, on turbulence and stochastic behaviors, on the development of chaos in dynamical systems, and on concepts of networks, nowadays frequently employed in climate research.

In this short course, we will offer a broad overview of the development and application of nonlinear concepts across the geosciences in terms of recent successful applications from various fields, ranging from climate to solar-terrestrial relations. The focus will be on a comparison between different methods to investigate various aspects of both known and unknown physical processes, moving from past accomplishments to future challenges.

Age models are applied in paleoclimatological, paleogeographic and geomorphologic studies to understand the timing of climatic and environmental change. Multiple independent geochronological dating methods are available to generate robust age models. For example, different kinds of radio isotopic dating, magneto-, bio-, cyclostratigraphy and sedimentological relationships along stratigraphic successions or in different landscape contexts. The integration of these different kinds of geochronological information often poses challenges.
Age-depth or chronological landscape models are the ultimate result of the integration of different geochronological techniques and range from linear interpolation to more complex Bayesian techniques. Invited speakers, Sebastian Breitenbach from CL division and Rachel Smedley from the GM division, will share their experience in several modelling concepts and their application in a range of Quaternary paleoenvironmental and geomorphologic records. The Short Course will provide an overview of age models and the problems one encounters in climate science and geomorphology. Case studies and practical examples are given to present solutions for these challenges. It will prepare the participants from CL, GM and other divisions for independent application of suitable age-depth models to their climate or geomorphologic data. For registration please send a request via this email address (ecs-cl@egu.eu) prior to 15th April.

Shaun Lovejoy (lovejoy@physics.mcgill.ca)
Christian Franzke (christian.franzke@gmail.com)
Thomas Laepple (Thomas.Laepple@awi.de)

The climate is highly variable over wide ranges of scale in both space and time so that the amplitude of changes systematically depends on the scale of observations. As a consequence, climate variations recorded in time series or spatial distributions, which are produced through modelling or empirical analyses are inextricably linked to their space-time scales and is a significant part of the uncertainties in the proxy approaches. Rather than treating the variability as a limitation to our knowledge, as a distraction from mechanistic explanations and theories, in this course the variability is treated as an important, fundamental aspect of the climate dynamics that must be understood and modelled in its own right. Long considered as no more than an uninteresting spectral “background”, modern data shows that in fact it contains most of the variance.

We review techniques that make it possible to systematically analyse and model the variability of instrumental and proxy data, the inferred climate variables and the outputs of GCM’s. These analyses enable us to cover wide ranges of scale in both space and in time - and jointly in space-time - without trivializing the links between the measurements, proxies and the state variables (temperature, precipitation etc.). They promise to systematically allow us to compare model outputs with data, to understand the climate processes from small to large and from fast to slow. Specific tools that will be covered include spectral analysis, scaling fluctuation analysis, wavelets, fractals, multifractals, and stochastic modeling; we discuss corresponding software. We also include new developments in the Fractional Energy Balance Equation approach that combines energy and scale symmetries.

In order to be able to have predictive power on extreme events we need to rely on mathematical approaches that provide us with some degree of universality, so that we have rigorous ways to extrapolate information beyond what has been already recorded. In this short course we will introduce frameworks based on dynamical systems theory and statistical mechanics that allow for a rigorous and effective treatment and analysis of extreme events. We will show how extreme value theory and large deviation theory allows for a better understanding of high-impact weather and climate extremes as well as of the basic dynamical properties of the atmosphere. We will introduce the basic theory and show applications on a range of datasets, including outputs of numerical models of various levels of complexity as well as observational data.

The climate system as a whole can be viewed as a highly complex thermal/heat engine, in which numerous processes continuously interact to transform heat into work and vice-versa. As any physical system, the climate system obeys the basic laws of thermodynamics, and we may therefore expect the tools of non-equilibrium thermodynamics to be particularly useful in describing and synthesising its properties. The main aim of this short course will be twofold. Part 1 will provide an advanced introduction to the fundamentals of equilibrium and non-equilibrium thermodynamics, irreversible processes and energetics of multicomponent stratified fluids. Part 2 will illustrate the usefulness of this viewpoint to summarize the main features of the climate system in terms of thermodynamic cycles, as well as a diagnostic tool to constrain the behavior of climate models. Although the aim is for this to be a self-contained module, some basic knowledge of the subject would be beneficial to the participants. Registration is not needed, but indication of interest would be helpful for planning purposes.