Present day climate is characterized by the presence of two ice sheets, one in each hemisphere, which is rare in the climate history of the Earth. This feature is strongly associated with the fact that during quaternary, the amount of GHG, especially atmospheric CO2 content in the atmosphere, was low compared to cenozoic's one. At the scale of centuries, the warming of high latitudes will be pivotal for humankind, but are we really able to diagnose such climate changes?
The warm climates of Cenozoic and Mesozoic offer the unique opportunity to investigate the climate behaviour in a rich GHG world. For many decades, a large number of scientists, from climate modeling groups to data reconstruction communities, have addressed several issues concerning the comparison of temperature simulations and proxies reconstructions for many warm periods at mid and high latitudes, but also between the surface and the bottom of paleo ocean. These efforts pointed out a large mismatch for mid and high latitude surface temperatures. Models largely under estimating temperature reconstructions derived from many terrestrial and oceanic proxies. A consequence was that the thermal gradient form equator to pole, which was very low by the reconstructions, has remained over estimated by the models, with a weak polar amplification. These issues have been exacerbated by Model Intercomparison Projects (MIP), which clearly pointed out that these mismatches were shared by most models (Pliomip for mid Pliocene and Deepmip for Eocene), and therefore, this mismatch can be considered as a robust feature.
This long-lasting paradox is associated with our ability to simulate earth's climate with a very low equator to pole temperature gradient compared to quaternary glacial inter-glacial cycles has been arising since the 1970s'. Therefore, it could be interesting to revisit this issue together with modelers of past warm climates and data people and discuss the plausible causes of this mismatch: lack of processes (cloud physics, GHG atmospheric content, aerosols...), but also uncertainties on data reconstructions. Moreover, this issue has important consequences for our ability to correctly understand and simulate the future climates, especially at high latitudes, and the interactions with ice sheets at scales of decades to centuries.

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 (cave deposits, palaeosols, snails), sediments (lakes, peatlands, rivers, alluvial fans), and biological materials (tree rings, fossil assemblages, bones, biomarkers). If you calibrate physical and chemical proxies that incorporate modern transfer functions, perform forward modeling and/or geochemical modeling to predict proxy signals, or attempt at quantitative estimates of past temperature and palaeohydrological dynamics you are mostly welcomed in our session! We are keen to invite reconstructions of temperature and hydrologic variability over large spatial scales, palaeoclimate data assimilation and monitoring studies leading to calibration or simply better understanding of climate proxies. Our session provides a forum for discussing recent innovations and future directions in the for continental palaeoenvironmental studies on seasonal to multi-millennial timescales.

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.

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 and radiochemistry in ice, among many others. Many climate and geochemical proxies have been identified from ice cores, with ongoing effort to extend their application and refine their interpretation. Great challenges remain in the field of ice coring sciences, including the identification of suitable sites for recovery of million-year-old ice; spatial integration of climate records (e.g. PAGES groups Antarctica2k and Iso2k); and deeper understanding of glaciological phenomena such as streaming flow, folding of layers and basal ice properties. 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.

What role did climate dynamics play in human evolution, the dispersal of different Homo species within and beyond the African continent, and key cultural innovations? Were dry spells, stable humid conditions, or rapid climate fluctuations the main driver of human evolution and migration? In order to evaluate the impact that different timescales and magnitudes of climatic shifts might have had on the living conditions of prehistoric humans, we need reliable and continuous reconstructions of paleoenvironmental conditions and fluctuations from the vicinity of paleoanthropological and archaeological sites. The search for the environmental context of human evolution and mobility crucially depends on the interpretation of paleoclimate archives from outcrop geology, lacustrine and marine sediments. Linking archeological data to paleoenvironmental reconstructions and models becomes increasingly important.

As a contribution towards a better understanding of these human-climate interactions the conveners encourage submission of abstracts on their project’s research on (geo)archaeology, paleoecology, paleoclimate, stratigraphy, and paleoenvironmental reconstructions. We especially welcome contributions offering new methods for dealing with difficult archive conditions and dating challenges. We hope this session will appeal to a broad audience by highlighting the latest research on paleoenvironmental reconstructions in the vicinity of key sites of human evolution, showcasing a wide variety of analytical methods, and encouraging collaboration between different research groups. Conceptual models, modelling results and model-data comparisons are warmly welcomed, as collaborative and interdisciplinary research.

This session aims to showcase an exciting diversity of state-of-the-art advances in all aspects of paleoceanography and paleoclimatology. We invite studies ranging across organic and inorganic geochemistry, sedimentology, and paleontology from marine and terrestrial environments, as well as multidisciplinary and modeling studies reaching into the future. We invite contributions that provide insight into the evolution of the Earth on short and long timescales, including how studies of paleoclimate and drivers can inform our current climatic changes and the implications for future Earth.

Carbonate (bio)minerals have been essential indicators for life throughout most of Earth’s history and are important archives for past climate and environmental change. Geochemical investigations are crucial for understanding (I) the paleobiology of carbonate biomineralizers, (II) the evolution of microbial habitats, and (III) complementary changes in the atmosphere-hydrosphere systems through time. With this session, we encourage contributions from sedimentology, geochemistry and (geo)biology that utilize carbonate (bio)minerals (e.g., invertebrate shells, foraminifera, microbialites and stromatolites) with the aim to reconstruct paleo-environments, seasonality, seawater chemistry and paleobiology in a wide range of modern to deep time settings, including critical intervals of environmental and climate change. This includes studies targeting original skeletal carbonate preservation and diagenetic alteration and theoretical or experimental studies of trace element partitioning and isotope fractionation in carbonate (bio)minerals.

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.

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.
Hamdi Omar will give an invited presetation on case studies of Phanerozoic Cyclostratigraphy in North Africa.

Several hyperthermal crises, i.e., times of sharp but short-term temperature rise, punctuated Earth history, and often coincided with marine and/or terrestrial mass extinctions. The largest occurred at the Permo-Triassic boundary 252 Myr ago when >80% of marine species went extinct, and more recent, smaller examples include the Palaeocene-Eocene Thermal Maximum. Studies on hyperthermal crisis have focused mainly on the oceans, but heating and acid rain had drastic effects also on land, stressing the terrestrial environments and killing plants and animals at all trophic levels. Understanding past hyperthermal crises may provide critical insight for our near future, in the context of anthropogenic warming and our rapidly changing planet.
Hyperthermal crises have remained a challenge to pin down, largely due to discrepancies among (and within) proxies and models, as well as the interpretation of that data. Furthermore, understanding the impact of temperature extremes and the unprecedented reorganisation of the hydrological cycle, palaeogeographic controls, and biotic condition have likewise remained a challenge. However, recent developments in dating, proxies, spatial/temporal resolution, and deep-time Earth system modelling are now shedding new light on common mechanisms and processes leading up to, during, and after these catastrophic events.
In this session, we welcome research regarding hyperthermal crises both from marine and terrestrial environments. Research may include (but not limited to) novel findings in fundamental geology (e.g., sedimentary response), proxy development (e.g., isotopic geochemistry), fossil interpretations (e.g., palaeontology), and paleoclimate Earth system modelling at a regional or global scale, aimed towards understanding paleoclimatic changes and their impact on biodiversity during hyperthermal intervals. Furthermore, we welcome comparative studies between hyperthermal events (including ocean anoxic events) in which investigators explore commonalities and consequences of high temperature on life and biogeochemical cycles, and how these consequences may scale to the magnitude of the temperature change.
We particularly welcome more data from terrestrial settings, both to 1) provide quantifiable evidence to mirror the effect of massive volcanism and related greenhouse gas input and 2) link hyperthermal crises with our current warming world (e.g., droughts, heatwaves, biodiversity crisis).

Today, the Indian, Pacific and Southern Oceans and associated ocean gateways capture the complex intermediate and deep-water return pathways of the global thermohaline circulation. The Indo-Pacific Warm Pool (IPWP) acts as a low latitude heat source for the polar regions and is a crucial part in globally significant climatic systems like the Australasian Monsoon, Intertropical Convergence Zone (ITCZ), El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). This highlights the Indo-Pacific’s importance in deciphering past and future coupled ocean-atmosphere dynamics.
The Cenozoic also sees large reorganisation of the hydrographic and atmospheric fronts across the Southern Hemisphere (SH). These changes have significant consequences for icesheet build-up in Antarctica and ocean-atmosphere carbon cycling, with further implications for surface ocean dynamics and productivity. Characterisation of these fronts using sedimentary records, located in mid-to-high latitudes in the SH allow us to understand the sensitivity and interconnection between Antarctic icesheets and carbon cycle to frontal shifts.
This session explores the role of the Indian, Pacific and Southern Oceans and their gateways in global climate change and as a biogeographic diversity hot spot from the geological past to the present. To understand the Cenozoic evolution of these Oceans and associated low- and high-latitude (especially SH) gateways, we invite submissions on wide-ranging topics including paleoclimatology, palaeoceanography, sedimentology, palaeontology, and data-model comparisons. This session will examine how feedbacks between the IPWP, Australasian hydroclimate and tectonic and/or weathering processes affect the evolution of the global monsoons and the ITCZ. We also encourage marine and/or terrestrial multi-proxy studies, investigating Cenozoic teleconnections of both equatorial Indo-Pacific (e.g., ENSO/IOD) and high latitude SH processes (e.g., variability of hydrographic fronts).

The geological record provides insight into how climate processes operate and evolve in response to different than modern boundary conditions and forcings. Understanding deep-time climate evolution is paramount to progressing on understanding fundamental questions of Earth System feedbacks and sensitivity to perturbations, such as the behaviour of the climate system under elevated atmospheric CO2 levels—relative to the Quaternary—, or the existence of climatic tipping points and thresholds. In recent years, geochemical techniques and Earth System Models complexity have been greatly improved and several international projects on deep-time climates (DeepMIP, MioMIP, PlioMIP) have been initiated, helping to bridge the gap between palaeoclimate modelling and data community. This session invites work on deep-time climate simulations and proxy-based reconstructions from the Cambrian to the Pliocene. We especially encourage submissions featuring palaeoenvironmental reconstructions, palaeoclimate modelling, and the integration of proxies and models of any complexity.

Time is a fundamental variable for the understanding of history and dynamics of Earth and planetary processes. Consequently, precise and accurate determination of crystallisation, deposition, exhumation or exposure ages of geological materials has had, and will continue to have, a key role in the geosciences. In recent years, substantial improvement in spatial and temporal resolution of well-established dating techniques and development of new methods have revealed previously unknown complexity of natural systems and in many cases revolutionised our understanding of rates of fundamental geologic processes.

With this session, we aim to provide a platform to discuss 1) advances in a broad spectrum of geochronological and thermochronological methods (sample preparation, analytical techniques, interpretational and modelling approaches) and 2) applications of such methods to a variety of problems across the Earth sciences, across the geological time and across scales of the process studied. We particularly encourage presentations of novel and unconventional applications or attempts to develop new geo/thermochronometers.

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 modeling, all across temporal and spatial scales.

Cave and karst formations such as speleothems, cave ice, cryogenic carbonate, sediments, tufa and travertines are important terrestrial archives of past environmental and climatic changes. They provide high resolution and accurately dated records using not only traditional geochemical tracers such as stable isotopes (d13C, d18O), trace elements, fluid inclusion analyses, or dead carbon fractions but also innovative methods such as organic markers or new paleothermometers. In recent years, the fields of cave and karst-based research has seen:
(1) Development of novel and innovative methods as well as continuously improving analytical capacity of established techniques allowing new applications also of traditional markers (e.g. combined multi-proxy approaches),
(2) Increasing numbers of long-term monitoring campaigns and cave-analogue experiments facilitating (quantitative) interpretation of proxy time series,
(3) Advancement of process and proxy-system models which are necessary to understand and disentangle proxy-relevant processes such as water infiltration, carbonate dissolution, degassing, precipitation, or diagenesis,
(4) The development and extensive use of databases such as SISAL (Speleothem Isotope Synthesis and AnaLysis) which enable regional-to-global and seasonal-to-orbital scale analyses of the relationships between proxies and environmental parameters,
Applied together, advancements in these cornerstones pave the way towards robust and quantitative reconstructions of climate and environmental variability. We invite cave- and karst-related modern and paleo studies to this session, which show progress in one of the four outlined domains. This comprises all integrated and interdisciplinary research helping to improve the understanding of the environment in which continental carbonates grow and the incorporation of climate-sensitive proxies at various time scales. In particular, this includes speleothem-based and other records using traditional proxies or novel markers and methods to reconstruct paleoclimate and paleoenvironment, data analysis studies and data-model comparisons. In addition, research contributing to current international co-ordinated activities, such as the PAGES working group on Speleothem Isotopes Synthesis and AnaLysis (SISAL) and others are welcome.

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 such as data assimilation or machine learning.

Soil is the function of soil forming factors. This basic principle of soil genesis lies behind the concept of soil memory: the capability of soil systems to imprint in their intrinsic features (environmental indicators) environmental conditions, thus keeping a memory of both current and past environments. Soils and paleosols can be studied to reconstruct environmental factors that were present during the time of their formation and to disentangle the relative influences of different environmental conditions, both local and regional, on soil formation.
Anthropogenic soils in archaeological settings provide valuable archives for geoarchaeological studies, with their stratigraphy and properties reflecting settlement life cycles (occupation, abandonment, and reoccupation) and land-use history. Land-use legacy soils also have enormous potential for process-related research.
Geophysical prospection and geospatial methods contribute to the detection and delimitation of buried structures as a prior step to an archaeological excavation, to the study of cultural heritage remains, and to paleosol and geoarchaeological studies.
This session is open to all contributions focused on the study of polygenetic soils and sediments; including paleosols, anthropogenic soils, and archaeological structures. The following aspects are of special consideration:
- The use of paleosols as records of present and former environments, both local and regional;
- Studies of soil memory linking pedogenesis and sedimentary processes;
- Anthropogenic soils and paleosols in archaeological contexts;
- Predictions of future soil changes as a result of changes in environmental conditions and/or land use, based on observed past soil responses to environmental changes;
- The methodological progress in the study of soil records (biochemical, geochemical, and micromorphological (sub-)microscopic techniques, interpretation of palaeoenvironmental data such as biomarker and isotope data, remote sensing or modelling methods, );
- Studies that combine geophysics (ground-penetrating radar, magnetics, electrical resistivity tomography, electromagnetic induction, seismics) with geospatial methods (photogrammetry, LIDAR, differential GNSS), to improve the data representation, increasing the understanding of the geophysical results;
- Studies of archaeological sites and structure characterization, with geophysical and geospatial methods, as well innovations in data acquisition and processing methods.

Fire is an essential feature of many ecosystems and an important component of the Earth system. Climate, vegetation, and human activity regulate fire occurrence and spread, but fires also feedback to them in multiple ways, resulting in changing fire regimes in many regions of the world. This session welcomes contributions that explore the role of fire in the Earth system at any temporal and spatial scale using modeling, field and laboratory observations, proxy-records including tree fire scars, sedimentary charcoal cores, ice cores, speleothems, and/or remote sensing. We encourage abstracts that advance our understanding on (1) fire related emissions (e.g. emission factors, emission height, smoke transport), (2) spatial and temporal changes of fire regimes in the past, present, and future, (3) fire products and models, and their validation, error/bias assessment and correction, (4) analytical tools designed to enhance situational awareness among fire practitioners and early warning systems. We are also welcoming submissions on fire related changes (5) in weather, climate, as well as atmospheric chemistry and circulation, (6) vegetation composition and structure, (7) cryosphere (e.g. permafrost, sea ice), (2) biogeochemical cycling of carbon, nitrogen and trace elements, (8) soil functioning and soil organic matter dynamics, as well as (9) effects of fires on humans (e.g., impact of fire on air and water quality, freshwater resources, human health, land use and land cover change, fire management).

Early career researchers and underrepresented groups in the field are strongly encouraged to apply.

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, variability, as well as its impacts and predictability in tropical and extratropical regions on (intra)seasonal, interannual, decadal timescales and beyond. They also make the basin particularly vulnerable to anthropogenic climate change, as well as related extreme weather and climate events, and their impacts for surrounding regions, home to a third of the global population. 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 observed and projected changes in Indian Ocean physical and biogeochemical properties and their impacts on ecological processes, diversity in Indian Ocean modes of variability (e.g., Indian Ocean Dipole, Indian Ocean Basin Mode, Madden-Julian Oscillation) and their impact on predictions, 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. We encourage submissions on weather and climate extremes of societal relevance in the Indian Ocean and surrounding regions, including evaluating climate risks, vulnerability, and resilience.

We also welcome contributions that address research on the Indian Ocean grand challenges highlighted in the IndOOS Decadal Review, and as formulated by CLIVAR, the Sustained Indian Ocean Biogeochemistry and Ecosystem Research (SIBER), the International Indian Ocean Expedition 2 (IIOE-2), findings informed by the Coupled Model Intercomparison Project v6 on past, present and future variability and change in the Indian Ocean climate system, and contributions making use of novel methodologies such as machine learning.

Regional monsoons and the global monsoon circulation to which they belong have profound impacts on water, energy, and food security. Monsoons cause severe floods and droughts as well as undergoing variability on subseasonal, interannual and decadal-to-multi-decadal time scales. In addition to profound local effects, monsoon variability is also associated with global-scale impacts via teleconnections.

Monsoons are among the most complex phenomena involving coupled atmosphere-ocean-land interactions and remain notoriously difficult to forecast at leads times ranging from numerical weather prediction (NWP) to long-term climate projections. A better understanding of monsoon physics and dynamics, with more accurate simulation, prediction and projection of monsoon systems is therefore of great importance.

This session invites presentations on any aspects of monsoon research in present-day, future and palaeoclimate periods, involving observations, modelling, attribution, prediction and climate projection. Topics ranging from theoretical works based on idealized planets and ITCZ frameworks to the latest field campaign results are also invited, as is work on impacts, extremes, NWP modelling, S2S and decadal forecasting, and the latest CMIP6 findings.

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.

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; decadal and paleo variability; theoretical approaches; ENSO diversity; global teleconnections; impacts on climate, society and ecosystems; seasonal forecasting and climate change projections of tropical mean state changes, ENSO and its tropical basins interactions. Studies aimed at evaluating and improving model simulations of ENSO, the tropical mean state and the tropical basins interactions basin are especially welcomed.

Phenological changes induced by ongoing climate change are affecting species, ecosystems, and even the global climate by altering species performance, species interactions (potential mismatches and new opportunities in the food web), and water and carbon cycles. Observations of plant and animal phenology as well as remote sensing and modeling studies document complex interactions and raise many open questions about the future sustainability of species and ecosystems.
In this session we invite all contributions that address seasonality changes based on plant and animal phenological observations, pollen monitoring, historical documentary sources, or seasonality measurements using climate data, remote sensing, flux measurements, modeling studies or experiments. We also welcome contributions addressing cross-disciplinary perspectives and international collaborations and program-building initiatives including citizen science networks and data analyses from these networks.
This session is organized by a consortium representing the International Society of Biometeorology (Phenology Commission), the Pan-European Phenology Network - PEP725, the Swiss Academy of Science SCNAT, the TEMPO French Phenology Network and the USA National Phenology Network.

This session explores climate change, extremes, processes and their impacts at local to regional scales, and the tools employed to investigate these phenomena. In particular, we welcome submissions advancing the state-of-the-art in the development and application of high-resolution models (convection-permitting, grid spacing ≤ 4 km) and high-resolution sub-daily data sets. Other high-resolution data sets such as land-surface, hydrology, vegetation or similar, and their impacts on local-scale climate change and extremes, are of further interest.

The session aims to bring together, amongst others, numerical modellers, the observational community and CORDEX-FPS participants, with the aim of advancing understanding of the aforementioned topics. Of particular interest are new insights which are revealed through high-spatiotemporal-resolution modelling or data sets. For example: convective extremes, physical mechanisms, fine-scale and feedback processes, differences in climate change signal, scale-dependency of extremes, interactions across scales and land-atmosphere interactions. Further, we welcome studies that explore local scale climate change in a variety of contexts whether they be past, present or future change. Studies that move towards an earth system approach – through incorporating coupled oceans, hydrology or vegetation – are especially encouraged.

Additional topics include, though are not limited to:
-- Mesoscale convective systems and medicanes
-- Event-based case studies (including surrogate climate change experiments or attribution)
-- Approaches for quantifying uncertainty at high resolutions including multi-model ensemble and combined dynamical-statistical approaches such as emulators
-- High-resolution winds and their impacts
-- Convection, energy balance and hydrological cycle including vegetation
-- Model setup and parametrization, including sensitivity to resolution, land surface and dynamics
-- Tropical convection and convective processes at local to regional scale
-- Model evaluation and new evaluation metrics/methods
-- Physical understanding of added value over coarser models
-- Severe storms including supercell thunderstorms and hailstorms
-- The roles of natural and internal variability

Extreme climate events have significant impacts on the environment and society. During recent decades, extreme climate events such as heatwaves, floods, droughts, extreme temperatures, heavy snowfall, and rainstorms have frequently occurred across the globe. These events have caused numerous casualties and enormous economic loss.
So far, the interannual-interdecadal variability and the long-term trend of extreme climate events have not been well understood. An important reason is that the mechanisms of extreme climate events are complex. For example, the tropical air-sea interaction, particularly ENSO, may induce flooding and/or droughts in Asia, North America, and Australia during summertime. Rapid changes in the Arctic climate including sea ice loss may induce cold surges and intense snowfall events in the mid-latitudes during the winter. However, the relationship between tropical air-sea interactions, polar climatic changes, and the occurrence of extreme climate events is poorly understood.
In addition, currently the prediction of extreme climate events is mostly poor. Better prediction of extreme climate events is urgently needed for public, which is particularly vital for decision-makers and stakeholders to devise appropriate and informed plans regarding climate change adaptation and climate disaster warning systems.
Thus, the aim of this session is to obtain a better understanding of the variability, mechanisms, and prediction of extreme climate events. We invite papers focusing on the historical changes of extreme climate events, the influences of air-sea-ice-land interaction on extreme climate events, and near-term prediction and projection of extreme climate events. Moreover, papers related to the observation, numerical simulation, attribution, and impacts of extreme climate events are also appreciated.

Urban areas play a fundamental role in local to large-scale planetary processes, via modification of heat, moisture, and chemical budgets. With urbanization continuing globally it is essential to recognize the consequences of landscape conversion to the built environment. Given the capabilities 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. Further, various adaptation and mitigation strategies aimed to offset impacts of rapidly expanding urban environments and influences of large-scale greenhouse gas emissions are being developed, implemented, and their effectiveness evaluated.
This session solicits submissions from both the observational and modelling communities. Submissions covering urban atmospheric and landscape dynamics, processes and impacts owing to urban-induced climate change, the efficacy of various strategies to reduce such impacts, human-biometeorological investigations in urban settings, 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 are welcome. Emerging topics including, but not limited to, citizen science, crowdsourcing, and urban-climate informatics are highly encouraged.

The interactions between the atmosphere, ocean and sea ice play an important role in shaping the polar climates. However, existing knowledge of the physical, chemical, and biogeochemical processes that underly the exchanges of mass, energy and momentum between these components remain poorly understood.

Closing knowledge gaps on the interactions between the atmosphere, ocean and sea-ice can considerably advance our ability to understand recent changes, and anticipate future changes in the Arctic and Antarctic climate systems. In particular, closing these knowledge gaps will improve our ability to represent them in our modelling systems and increase confidence in projections of future climate change in the polar regions.

This session will highlight 1) recent advances in our knowledge of atmosphere-ocean-sea ice interactions and 2) new and emerging tools and datasets that can close these knowledge gaps.

We welcome observational and numerical modelling studies of physical and chemical atmospheric and ocean processes that underly interactions in the coupled climate system in both the Arctic and Antarctic. This includes but is not limited to:

Cloud microphysics and aerosol-cloud interactions, and their role in the coupled system;
Atmospheric Boundary Layer (ABL) dynamics and its interactions with the sea-ice surface;
Sea ice dynamics and thermodynamics, e.g. wind driven sea-ice drift, snow on ice;
Upper ocean mixing processes;
Sea ice biogeochemistry and interactions at interfaces with sea ice;
Snow on sea ice and it’s role in the coupled ocean-ice-atmosphere system;
Surface energy budget of the coupled system, including contributions of ABL-dependent turbulent fluxes, clouds and radiative fluxes, precipitation and factors controlling snow/sea ice albedo.
Presentations showcasing recent or emerging tools, observational campaigns, or remote sensing datasets are encouraged.

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 decade, several observational projects have been focused on the Atlantic circulation changes, for instance ACSIS, OSNAP, OVIDE, RACE and RAPID, and new projects have started such as CANARI and EPOC. Most of these programs include also a modelling component. 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.

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

The Paris Agreement long-term temperature goal sets ambitions for global climate action to avoid the most devastating impacts of climate change. However, under current emissions trajectories, overshooting 1.5°C or 2°C is likely. The IPCC AR6 WG2 Summary for Policymakers (SPM) refers to overshoot scenarios as the “pathways that first exceed a specified global warming level (usually 1.5°C, by more than 0.1°C), and then return to or below that level again before the end of a specified period of time (e.g., before 2100).

Specific risks inherent to overshoot scenarios have so far been under-researched. Those risks can for example be related to the feasibility of the large-scale deployment of negative emissions technologies which often underlie such scenarios, the potential non-linear evolution of climate impacts with GMT that could lead to irreversible outcomes even in cases where global warming is reverted, as well as to their implications for (mal)adaptation.

In this session we want to discuss research on:
*) The conditions that could lead to overshoot scenarios, and more generally their feasibility
*) Climate impacts in overshoot scenarios
*) The mechanisms that could lead to impacts evolving non-linearly with GMT in such scenarios, such as in systems characterized by non-linearities, hysteresis or irreversibilities
*) The implications of overshoots for adaptation planning

Nature-Based Solutions (NbS) are actions to protect, sustainably manage, and restore natural or modified ecosystems, that address societal challenges, simultaneously providing human well-being and biodiversity benefits (IUCN, 2018). Within the framework of a global ecosystem approach, NbS must encompass ecological, societal, political, economic and cultural issues at all levels, from the individual to the collective, from local to national, from the public or private sphere.

As recently highlighted by IPCC and IPBES, climate change and biodiversity degradation cannot be separated, and must be considered together. For this reason, this session is especially focused on the way NbS can act as climate change adaptation solutions. Considering various ecosystems (marine and coastal, urban, cropland, mountainous, forest, rivers and lakes,.,), NbS as interventions for climate adaptation includes the adaptation to: sea level rise (flooding and erosion), changes of the water regime (floods, droughts, water quality and availability), rise in temperatures (heat waves, forest fires, drought, energy consumption), plant stress and increase of pests (variation of yields, forest dieback), to minimize their associated social and economic negative impacts.

Therefore, this session aims to promote interdisciplinary research related to ecosystem restoration, preservation and management, to put forward the complexity that is often hidden by simplifying hypotheses and approaches (sector-based silo approach, homogeneity of environments, ...).

Specific topics of interest are the followings:
- Complexity: nature of ecosystems and the risk of oversimplification, interconnection between NbS and complementary areas, consideration of uncertainties (future climate and associated impacts...)
- Scales: spatial scales with the integration of NbS in their environment, and temporal scales considering sustainability over time, variability of bio-physical processes and climate change effects
- Ecosystem services: understanding the bio-geophysical processes, spatial shift between the location of NbS and the location of beneficiaries, modification under climate change (threshold and inflection point), co-benefits or on the contrary degradation, negative effects ("misadaptation")
- Assessment and indicators: measurement and modelling protocols to evaluate NbS performances, capacity to measure the complexity, resilience and stability of the solutions.

Land use and land cover change (LULCC), including land management, has the capacity to alter the climate by disrupting land-atmosphere fluxes of carbon, water and energy. Thus, there is a particular interest in understanding the role of LULCC as it relates to climate mitigation (e.g., CO2 removal from the atmosphere) and adaptation (e.g., shifts in land use or management) strategies. Recent work has highlighted tradeoffs between the biogeophysical (e.g. changes in surface properties such as albedo, roughness and evapotranspiration) and biogeochemical effects (e.g., carbon and nitrogen emissions) of land management and change on weather and climate. However, characterizing the relationship between these effects with respect to their extents and the effective net outcome remains challenging due to the overall complexity of the Earth system. Recent advances exploiting Earth system modelling and Earth observation tools are opening new possibilities to better describe LULCC and its effects at multiple temporal and spatial scales. An increasing focus on land-based mitigation and adaptation strategies to meet more stringent emissions targets has expanded the range of land management practices considered specifically for their potential to alter biogeophysical and biogeochemical cycles. This session invites studies that improve our understanding of LULCC-related climate and weather perturbations from biogeophysical and biogeochemical standpoints, either separately or focused on the intersection between these two factors. This includes studies focusing on LULCC that can inform land-based climate mitigation and adaptation policies. Observation-based and model-based analyses at local to global scales are welcome, including those that incorporate both modeling and observational approaches.

The state of the planet, especially climate and ocean (C&O), has become even more dire than just a year ago. Some quotes (mostly 2022) will illustrate this:
• The world is halfway through the time allocated for achieving the SDGs and the UN reports [that] countries have gone backwards on most of them. Bendell.
• Our world is suffering from the impact of unprecedented emergencies caused by the climate crisis, pollution, desertification and biodiversity loss. UN Secr-General, Guterres.
• Multiple climate tipping points could be triggered if global temperature rises beyond 1.5°C above pre-industrial levels. This will be disastrous for people across the world. futureearth.org, McKay, Rockström.

System-wide C&O education, with a good dose of geoethics, is a crucial key to reducing the impending tragedy. Thus C&O educators carry a great geoethical responsibility for the health of the Earth and the life that it carries, including humans. This also is a well-supported idea:
• Climate literacy is the key to a greener future. Conner.
• Understanding human behavior and the social drivers of climate change are essential for the public to fully appreciate the climate system. Shwom et al.
• Improved science and climate literacy are needed for planetary citizens to better understand the implications of global change. Harrington.
• Creating a climate-literate population is key to driving green jobs – and ambitious climate action. earthday.org
• It is about empowering people with tools, to better use that ocean knowledge to become more responsible and able to take decisions that involve ocean resources. Santoro, 2022.

The state of the climate and the related urgent need for climate education are captured in this quote:
• Since the IPCC (2018) 1.5°C Report, the global climate emergency has become widely acknowledged. With all adverse climate change indicators at record highs and global emissions still increasing, political will needs to be driven, hard and fast, making climate change literacy a survival imperative for civilization. Carter.

The above can be applied, mutatis mutandis, to related threats, such as biodiversity, pollution, food security and fossil-fuel-driven war. We welcome presentations from all cultures on a broad range of topics, from hands-on pedagogical methods and practices, through geo-communication, curriculum matters, outreach and research, to policy and its implementation.

A wide range of processes influence the response of the vegetation, soils, and terrestrial carbon fluxes to changes in land and atmospheric moisture availability. Such responses also occur over a wide range of time scales, ranging from extreme events like floods, droughts or heatwaves, to long-term shifts in background climate. In addition, the vegetation and soils regulate land-atmosphere moisture and energy fluxes, which in turn feed back to the broader climate system.

Advances in remote sensing, experimental studies, and the growing number of in situ measurements and ecosystem trait databases can now be combined with machine learning, statistical approaches and/or mechanistic models, to understand how plants, soils, and ecosystems respond to climate variability. Combining these data in innovative ways will help to evaluate and improve models of plant-stress and carbon exchange, and in-turn climate projections.

Contributions might include, for example, regional to global evaluations of the vegetation and ecosystem response to various environmental stressors (e.g. soil moisture, temperature, etc.) and climatic variability, using in-situ and/or satellite observations to evaluate or improve the representation of water-carbon interactions and biological processes in models, new representations of plant and ecosystem response to land and atmospheric moisture stress (e.g. through plant hydraulics, optimality approaches, etc.), and improvements in our understanding of how soils and plant-stress regulate surface fluxes and boundary layer processes.

Solicited authors:
Charlotte Grossiord, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
René Orth, Max Planck Institute for Biogeochemistry, Jena, Germany

The session will explore a wide range of key research (and policy) questions for blue carbon, carbon stored in marine and coastal ecosystems. This will support understanding of adaptation and mitigation processes within marine, small islands, and coastal ecosystems.
Since 196 Parties to the Paris Agreement committed to transforming their development trajectories towards sustainability and called for limiting global warming to well below 2°C – ideally 1.5°C – above pre-industrial levels, to meet these goals, global carbon dioxide emissions need to be reduced by 45% by 2030 and reach net zero by 2050. Global averages for carbon pools (soil organic carbon and living biomass) of focal coastal habitats. Carbon is stored in three coastal habitats, seagrass meadows, salt marshes, and mangroves, which are thought to be the largest repositories of carbon in marine and coastal ecosystems. Marine and coastal ecosystems, including small islands that are the interface between the terrestrial and marine ecosystems and are directly affected by climate change for relatively short periods, sequester and store more carbon per unit area than terrestrial forests and are now being recognized for their role in mitigating climate change.

IPCC has admitted Blue Carbon as carbon fluxes and storage in marine and coastal ecosystems. All biologically driven carbon fluxes and storage in marine and coastal ecosystems amenable to management can be considered blue carbon.
Therefore, we see blue carbon as an opportunity to contribute to global carbon reduction and climate change mitigation objectives.

This session invites researchers to work on:
1. Carbon uptake capabilities of marine, small islands, and coastal ecosystems
2. Functions of the marine, small islands, and coastal ecosystems
3. Comparison between coastal and terrestrial ecosystems by remote-sensed and in-situ observational, experimental, conceptual, and modeling approaches
4. Spatial and temporal changes of coastal ecosystems (marine, small islands, and coastal areas) in the past, present, and future

Geoscience expertise is essential for the functioning of modern societies, to address many of the most urgent global problems, inform decision-making, and guide education at all levels, by equipping citizens to discuss, shape and implement solutions to local, regional and global social-environmental problems. In recent years, geoscientists have become more and more aware of ethical responsibilities to put their knowledge at the service of society, foster public trust in geosciences, and reflect on the environmental footprint of research practices. Geoethics aims to provide a common framework for orienting geoscientists’ concerns on delicate issues related geoscience-society interaction and to nourish a discussion on the fundamental principles and values which underpin appropriate behaviors and practices, wherever human activities interact with the Earth system.
The goal of the session is to foster the discussion on the following spectrum of topics:
- philosophical and historical aspects of geoscience, their contemporary relevance and role in informing methods for effective and ethical decision-making;
- geoscience professionalism and deontology, research integrity and issues related to harassment and discrimination, gender and disability in geosciences;
- ethical and social questions related to the management of land, air and water including environmental changes, pollution and their impacts;
- socio-environmentally sustainable supply of georesources (including energy, minerals and water), importance of effective regulation and policy-making, social acceptance, and understanding and promoting best practices;
- questioning professional practices in geosciences and their impact on the environment, and implementation of new practices to reduce it;
- resilience of society related to natural and anthropogenic hazards, risk management and mitigation strategies, including adaptation knowledge and solutions;
- ethical aspects of geoscience education and communication;
- culture and value of geodiversity, geoconservation, geoheritage, geoparks and geotourism;
- role of geosciences in achieving socio-economic development that respects cultures, traditions and local development paths, regardless of countries' wealth, and in promoting peace, responsible and sustainable development and intercultural exchange.
Session sponsored by International Association for Promoting Geoethics (www.geoethics.org).

Soils have a tremendous potential to mitigate and build resilience to climate change. However, key challenges about how to adapt, improve and optimize land management practises in order to maximize the potential soil ecosystem services whilst maximizing carbon sequestration. Particular challenges lie in soils that are subject to anthropogenic activities such as intensive agriculture, forestry or urbanization. Furthermore, spatial heterogeneity across different scales and environmental settings constitutes another challenge to extrapolate findings and build robust land use management strategies.
Increasing efforts are dedicated towards instrumentalising soils to sequester carbon whilst retaining or increasing productivity (e.g. the “4 per 1000" initiative), or increasing resilience (e.g. by reducing land degradation). From a governance perspective on a European level there is increasing interest in safeguarding soils as a strategic resource (e.g. EU Green Deal, European Joint Programme SOIL) to contribute to the ambitions of Zero Pollution agriculture and Farm to Fork Strategies, as well as the UN Sustainable Development Goal 13: Take urgent action to combat climate change and its impacts.
This session aims to discuss the potential for soils to contribute to climate neutrality and build resilience to climate change while maximising the synergy with soil health, and a clean environment. We welcome research including experimental and modelling studies addressing the following subjects:
- Studies on soil carbon sequestration related to management practises (e.g. tillage or fertilisation) especially from short- or long-term changes;
- Interactions between Climate Neutrality and land degradation reduction;
- Integration of digital tools, artificial intelligence and models in soil science to better support soil-related decision-making processes in achieving climate neutrality and climate resilience;
- Novel approaches to evaluate key soil ecosystem services such as soil carbon sequestration, water retention or nutrient cycling in integrative approaches for sustainable land use.

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 transformation, 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.

Attribution research assesses how anthropogenic and natural forcings may contribute to observed changes in the climate system as well as ensuing changes in natural, managed, and human systems. With regard to observed climatic trends, Detection and Attribution (DA) studies aim to identify historical changes over long timescales (typically multi-decadal), and quantify the contributions of various external forcings as their signal emerges above internal climate variability. Event attribution (EA) assesses how anthropogenic climate change may be modifying characteristics like the frequency and intensity of weather and climate extreme events. This rapidly evolving scientific area has introduced a range of methodologies and different ways of framing attribution questions. Impact attribution in turn aims to assess in a quantitative manner the contribution of anthropogenic climate change to observed changes in natural, managed, or human systems, extending existing concepts as well as calling for new approaches, given the added complexity from non-climatic human influences on many of these systems.
This session includes recent studies from the spectrum of DA research that address any or all steps of the forcing-climate-impact chain and aims to explore the diversity of methods employed across disciplines and schools of thought.
Trend and EA studies will consider a wide range of temporal and spatial scales. We thereby aim to identify common and new methods, including approaches based on statistical causality or AI, current challenges, and avenues for expanding the detection and attribution community. We particularly welcome submissions that compare approaches, address hydrometeorological trends, extremes, including compound/cascading events and/or assess implications of recent trends for constraining future changes – all of which test the limits of the present science.
We also welcome studies that go beyond climatic phenomena by attributing observed changes and events in natural, managed, and/or human systems. Examples include the attribution of observed socio-economic impacts (e.g., food price) via changes in the biophysical system (e.g., agricultural drought) driven by greenhouse gas emissions. Studies may also restrict their analysis to parts of the climate-impact chain, such as attributing an observed biophysical impact (e.g., species migration) to observed climate change.

Climate change and its manifestations and consequences vary from region to region, especially for climate extremes, due to complex regional interplays among human influence, internal climate variability, and land-atmosphere interaction/feedback. The climate extremes contain heat waves, cold outbreaks, droughts, floods, blizzards, windstorms, amongst others.

The accurate detection of changes in regional climate extremes is sometimes difficult due to observation uncertainties, such as non-climatic discontinuities in the data series and the scarcity of observations in regions such as Africa or at high altitudes. Reliable attribution of regional climate extremes usually depends on model skills in simulating such extremes. Global models actually provide some useful evidence for the role of human influence in regional climate extremes, while regional climate models could increase the confidence of attribution to internal climate variability or regional forcings such as land use/cover. In addition, the attribution uncertainties could be caused by different attribution methodologies used, e.g., optimal fingerprinting or Bayesian statistics, and different model strategies employed, e.g., multi-models or single-model large ensembles.

This session provides a venue to present the latest progress in reliable detection, modelling, and attribution of regional climate extremes, especially in quantifying or reducing their uncertainties for better risk management. We welcome abstracts focused on, but not limited to:
- address the quality issue of daily observation data relevant at the regional scale
- assess the fitness of global or regional modelling by designing tailored diagnostics for climate extremes and their drivers in a regional context
- improve climate models to realistically represent regional climate extremes, in particular to convection-permitting scale at a fine resolution or to mega-heatwaves by adding relevant land-atmosphere feedbacks
- reveal and evaluate the strengths and weaknesses of attribution methodologies used for different regional climate extremes
- develop new detection and attribution techniques for regional climate extremes, e.g., employ advanced machine learning algorithms to extract spatial features
- find key physical or causal processes to constrain the attribution uncertainties
Finally, abstracts associated with projection uncertainties of regional climate extremes are also appreciated.

The big question confronting climate science today is how ongoing climate changes could influence extremes in regional meteorological and hydrological systems over decadal timescales. Extreme events, such as floods, droughts and heatwaves, are deadly and costly phenomena. Within Europe, although all countries are already affected by climate change and the impacts of extremes, the southeastern region remains under-studied. This lack of knowledge limits the options available to politicians and stakeholders there, who must decide which measures to take to guard against the risk of those extreme events.

This session is devoted to the reduction of the uncertainties in the decision chain (i.e., data, methods, results and impacts). The advancement is assumed to come from novel measurement data, improved climate and hydrology models output, state-of-the-art statistical methods and machine-learning algorithms in support of decision-making in a situation of uncertainty. We warmly welcome contributions on the decision chain for the broadly defined Southeast European region.

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

In this session we propose to group together the traditional geophysical sciences and more mathematical/statistical and impacts-oriented approaches to the study of extremes. We aim to highlight the complementary nature of these viewpoints, with the aim of gaining a deeper understanding of extreme events. This session is a contribution to the EDIPI ITN, XAIDA and CLINT H2020 projects, and we welcome submissions from both project participants and the broader scientific community.

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

· Dynamical systems theory and other theoretical perspectives on extreme events;
· Data-driven approaches to study extreme events, incl. machine learning;
· Representation of extreme events in climate models;
· Downscaling of weather and climate extremes;
· How extremes have varied or are likely to vary under climate change;
· Attribution of extreme events;
· Early warning systems and forecasts of extreme events;
· Linking the dynamics of extreme events to their impacts.

Remaining carbon budgets specify the maximum amount of CO2 that may be emitted while stabilizing warming at a particular level (such as the 1.5°C or 2.0°C target), and are thus of high interest to the public and policymakers. Estimates of the remaining carbon budget come with associated uncertainties, which increase in relative terms as more ambitious targets are being considered, or as emission reductions continue to be delayed. As a result, practical implementation of remaining carbon budgets is challenging.

This session aims to further our understanding of the climate response under various emission scenarios that aim to inform the goals of the Paris Agreement, with particular interest in emission pathways entailing net-zero targets. We invite contributions that use a variety of tools, including fully coupled Earth System Models (ESMs), Integrated Assessment Models (IAMs), or simple climate model emulators, that advance our knowledge of remaining carbon budgets, net-zero targets, and policy implications.

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, we welcome contributions on the zero emissions commitment (ZEC), 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 keep warming below a given temperature target, the role of pathway dependence and emission rate, the climate-carbon responses to different emission scenarios (e.g. RCP or 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 and quantifying the impact of climate change on natural and socio-economic outcomes supports decision making across scales including national and international energy, agriculture, and health policy. However economic, econometric and integrated assessment models of climate impacts rely on multiple components, including climate models, damage functions, and policy responses, each of which comes with its own modelling challenges and uncertainties. Owing to the overall complexity of the coupled socio-economic-Earth system, many individual components must be simplified while robustly capturing the large-scale dynamics of the system. The climate component is a case in point, with reduced-complexity modelling, including regional climate, extremes, and impacts, an emerging field in its own right.

We invite research on all aspects of the development and application of simple climate and climate-economic models. This includes but is not limited to: the development and results of emulators; the role of simple climate models in integrated assessment and scenario generation; the development and results of economic, econometric and integrated assessment models of climate change; strategies to replicate socio-economic and/or natural spatio-temporal variability, feedbacks, tipping points, and policy effects evidenced in complex Earth System and Socio-economic models; and uses of economic and simple climate models in outreach, education and policymaking.

In 2015, the UN Sustainable Development Goals and the Paris Agreement on climate recognized 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 and interactions between the carbon cycle, the atmosphere, oceans, large-scale ecosystems, and the cryosphere, as well as the dynamics and perturbations associated with human activities.

With rising anthropogenic pressures, there is an increasing risk we might be hitting the ceiling of some of the self-regulating feedbacks of the Earth System, and cross tipping points which could trigger large-scale and partly irreversible impacts on the environment, and impact the livelihood of millions of people. Potential domino effects or tipping cascades could arise due to the interactions between these tipping elements and lead to a further decline of Earth resilience. At the same time, there is growing evidence supporting the potential of positive (social) tipping points that could propel rapid decarbonization and transformative change towards global sustainability.

In this session we invite contributions on all topics relating to tipping points in the Earth system, positive (social) tipping, as well as their interaction and domino effects. We are particularly interested in various methodological approaches, from Earth system modelling to conceptual modelling and data analysis of nonlinearities, tipping points and abrupt shifts in the Earth system.

Recent extreme events with intensities unprecedented in the observational record are causing high impacts globally, such as the heat waves in the UK, Pacific Northwest and in parts of China and severe flooding in Pakistan, Western Europe, eastern US and across China. Some of these events would have arguably been nearly impossible without human-made climate change and broke records by large margins. Furthermore, compound behaviour, cascading effects and complex risks are becoming evident, such as the spike in food prices induced by the effects of the war in Ukraine on top of concurrent drought across regions with subsequent crop failure. Finally, continuing warming potentially increases the risk of crossing tipping points and triggering abrupt changes. In order to increase preparedness for high impact climate events, it is important to develop methods and models that are able to represent these events and the impacts from them, and to better understand how to reduce the risks.

This session aims to bring together the latest research on modelling, understanding and managing plausible past and future high impact climate events. We are interested in rare and low-probability heavy precipitation events, droughts, floods, storms and temperature extremes from time scales of hours to decades, including compound, cascading, and connected extremes, as well as the effect of tipping points and abrupt changes driven by climate change, societal response, or other mechanisms (e.g., volcanic eruption). We are interested both in these events from the perspective of the interactive earth system per se, and on their impacts, consequences, and management perspectives.

We welcome a wide variety of methods to quantify and understand high-impact climate events in the present and future climate, such as through model experiments and intercomparisons; insights from paleo archives; climate projections (including large ensembles, and unseen events); attribution studies; and the development of storylines. We invite work on tipping elements/tipping points; abrupt changes; worst case scenarios; identification of adaptation limits; and the opportunities and solutions to manage the greatest risks.

This session is informed by the World Climate Research Programme lighthouse activities on Safe Landing Pathways and Understanding High-Risk Events.

The conservation, protection, and fruition of cultural heritage are closely related to the environmental setting and its variability. Historical objects, structures, and sites worldwide interact with a broad diversity of environments, on the surface (outdoors or indoors), underground, or underwater. As the characteristics of the Earth’s systems vary in space and time, also in view of climate change, so does the behavior of the materials shaping the cultural assets.
This session addresses the interaction between cultural heritage and the environment from the interdisciplinary perspective of geosciences, which represent a valuable support for investigating the properties and durability of the component materials (e.g., stones, ceramics, mortars, pigments, glasses, and metals); their vulnerability and changes in weathering dynamics; the influence of key environmental variables associated with climate, microclimate, and composition of air, waters, and soils; the impact of global warming, sea level rise, ocean acidification, and extreme weather events; the techniques and products to improve conservation practices; and the adaptation measures for heritage protection. This session welcomes contributions with an explicit and direct connection with environmental issues and questions. The possible research approaches include but are not limited to field and laboratory analysis and testing; damage assessment, observation, and simulation; modeling of decay and risk scenarios; strategies of monitoring and remote investigation; hardware/software design for collecting and processing environmental databases.

There are multiple environmental pathways that impact human, animal, and plant health. Increasing climatic variability, including extreme weather events, coupled with human-environmental interactions leads to increased risks of disease outbreaks including vector- (e.g. Zika, Dengue, Chikungunya, Malaria, Rift Valley Fever), water- (e.g. Cholera, Dysentery, Typhoid) and air-borne (e.g. Coronavirus, Influenza) diseases. These phenomena have a spatiotemporal distribution driven by the interactions of climate and environmental variables (e.g. precipitation, specific humidity, runoff, vegetation indices) with that of the vectors and hosts of each individual disease. This session is seeking research that advances the state-of-the-art in disease early warning. This can range from developing the system for which these disease models can reside to advancing the science behind individual routes of transmission using climatic, weather, and remote sensing data products.

Already today, many coastal cities face high economic and non-economic losses from disasters and creeping environmental changes. However, risks in coastal cities are expected to rise even further, fuelled by the interplay of climate change and continued coastal urbanization. The question of how to adapt cities to the hazards of the future is therefore of great concern – not only for scientists, but also for policy makers and risk practitioners. The relevance of this question even increases when considering the central role of coastal cities in economies and societies at the global scale, for instance, in terms of trade, transport, and culture.

A number of important scientific knowledge gaps persist with regards to risk assessment and adaptation analysis in coastal cities. While the assessment of future risk trends in these cities is predominantly focused on scenarios of future hazards (sea level rise, floods, typhoons, etc.), scenarios of socio-economic changes and hence future trends in exposure and vulnerability are typically not part of the picture. This lack is significant and leads to potentially flawed and imprecise assessments of future risk trends and eventually adaptation needs. Secondly, knowledge on the feasibility of different – often competing – adaptation options remains thin. It is too often based on a reductionist set of evaluation criteria, e.g. economic costs and benefits, and a view towards singular adaptation measures. Integrative and comparative assessments that evaluate different adaptation options (e.g. retreat vs. flood accommodation) against a wider set of criteria such as social acceptance or political feasibility are still poorly developed. Thirdly, scientific engagement with coastal urban risk too often remains within siloes of different disciplines. This hampers interdisciplinary assessments and leads to significant blind spots, e.g. with respect to private sector adaptation or collective action for adaptation across different groups of actors.

We particularly invite theoretical, methodological, and empirical studies to better understand future risk in coastal cities and potential adaptation strategies. Both local case studies, regional- and global-level perspectives from multi- and trans-disciplinary studies are welcome. A particular focus will be on coastal cities with high growth dynamics and adaptation pressure, as can be observed in many transition economies of Asia and Africa.

Long-term climate change, extreme events, and seasonal variations in weather have profound impacts on water quality of rivers, lakes, and reservoirs. This implies a pressing need for tools anticipating the impacts of these environmental changes, and enabling effective water management that safeguards the ecosystem goods and services freshwaters provide. Scientific studies typically omit the impacts of climate on water quality. To tackle this gap, this session looks for research results related to the impact of climate change on water quality. We welcome climate attribution results, studies using data-driven and remote sensing techniques and model projects of climate change from local to global scales. We are also interested in water quality studies within the regional and global water sectors Inter-Sectoral Impact Model Intercomparison Program (ISIMIP).

Hydroclimatic conditions and availability of water resources in space and time constitute important factors for maintaining adequate food supply, the quality of the environment, and the welfare of citizens and inhabitants, in the context of a post-pandemic sustainable growth and economic development. This session is designed to explore the impacts of hydroclimatic variability, climate change, and temporal and spatial availability of water resources on different factors, such as food production, population health, environment quality, and local ecosystem welfare.
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.
• Smart infrastructure for water usage, reduction of water losses, 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 supply, 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 forcing (e.g. inappropriate agricultural practices, and land usage) on the natural environment (e.g. health impacts from water and air, fragmentation of habitats, etc.)

Traditionally, hydrologists focus on the partitioning of precipitation water on the surface, into evaporation and runoff, with these fluxes being the input to their hydrologic models. However, more than half of the evaporation globally comes back as precipitation on land, ignoring an important feedback of the water cycle if the previous focus applied. Land-use and water-use changes, as well as climate variability and change alter, not only, the partitioning of water but also the atmospheric input of water as precipitation, related with this feedback, at both remote and local scales.

This session aims to:
i. investigate the remote and local atmospheric feedbacks from human interventions such as greenhouse gasses, irrigation, deforestation, and reservoirs on the water cycle, precipitation and climate, based on observations and coupled modelling approaches,
ii. investigate the use of hydroclimatic frameworks such as the Budyko framework to understand the human and climate effects on both atmospheric water input and partitioning,
iii. explore the implications of atmospheric feedbacks on the hydrologic cycle for land and water management.

Typically, studies in this session are applied studies using fundamental characteristics of the atmospheric branch of the hydrologic cycle on different scales. These fundamentals include, but are not limited to, atmospheric circulation, humidity, hydroclimate frameworks, residence times, recycling ratios, sources and sinks of atmospheric moisture, energy balance and climatic extremes. Studies may also evaluate different sources of data for atmospheric hydrology and implications for inter-comparison and meta-analysis. For example, observations networks, isotopic studies, conceptual models, Budyko-based hydro climatological assessments, back-trajectories, reanalysis and fully coupled earth system model simulations.

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.

A predictive knowledge of fault and fracture zones and their transmissibility can have an enormous impact on the viability of geothermal, carbon capture, energy and waste storage projects. Understanding the role and the effects played by fault and fracture zones, physical properties of the system (e.g. frictional strength, cohesion and permeability) on the in-situ fluid behaviour can generate considerable advantages during exploration and management of these reservoirs and repositories. Generating realistic models of the subsurface requires detailed information on the deformation processes, structure and properties of fault and fracture zones. To create accurate and realistic models, we need to characterise the geometry and the distribution of faults and fractures, as well as the mechanical and petrophysical properties of the fractured rocks. The properties and the evolution of faulted/fractured rocks can be evaluated using a combination of laboratory data, well data and outcrop analogues which then constitute the backbone of discrete fracture network (DFN) modelling and robust numerical flow models.

We encourage researchers on applied or interdisciplinary energy studies associated with low carbon technologies (geothermal, repositories, hydrogeology, CCS) and modelling of fractured media (e.g. DFN) to come forward for this session. We look forward to interdisciplinary studies which use a combination of methods to analyse rock deformation processes and the role of faults and fractures in subsurface energy systems, including but not restricted to outcrop studies, laboratory measurements, analytical methods and numerical modelling. We are also interested in studies working across several different scales and that try to address the knowledge gap between laboratory scale measurements and reservoir scale processes.

This session aims to share innovative approaches to multi-hazard risk assessments and their components (hazard, exposure, vulnerability and capacity), and to explore their applications to disaster risk reduction.

Effective disaster risk reduction practices and the planning of resilient communities requires the evaluation of multiple hazards and their interactions. This approach is endorsed by the UN Sendai Framework for Disaster Risk Reduction. Multi-hazard risk and multi-hazard impact assessments look at interaction mechanisms among different natural hazards, and how spatial and temporal overlap of hazards influences the exposure and vulnerability of elements at risk. Moreover, the uncertainty associated with multi-hazard risk scenarios needs to be considered, particularly in the context of climate change and slow-onset hazards, such as Covid-19 and pandemics in general, characterized by dynamic changes in exposure and vulnerability that are challenging to quantify.

This session, therefore, aims to profile a diverse range of multi-hazard risk and impact approaches, including hazard interactions, multi-vulnerability studies, and multi-hazard exposure characterization. In covering the whole risk assessment chain, we propose that it will be easier to identify potential research gaps, synergies and opportunities for future collaborations.

We encourage abstracts which present innovative research, case study examples and commentary throughout the whole disaster risk cycle on (i) multi-hazard risk methodologies which address multi-vulnerability and multi-impact aspects; (ii) methodologies and tools for multi-hazard risk management and inclusive risk-informed decision making and planning; (iii) methodologies and tools for multi-hazard disaster scenario definition and management for (near) real-time applications; (iv) cross-sectoral approaches to multi-hazard risk, incorporating the physical, social, economic, and/or environmental dimensions; (v) uncertainty in multi-hazard risk and multi-hazard impact assessment; (vi) evaluation of multi-hazard risk under future climate and slow-onset hazards, including pandemics; (vii) implementation of disaster risk reduction measures within a multi-hazard perspective.

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.

One of the most striking signatures of climate change is polar amplification – the greater warming of the polar regions than the global average - which may have implications for weather and climate at lower latitudes. The session will showcase emerging results from the Polar Amplification Model Intercomparison Project (PAMIP), which has provided coordinated multi-model large ensemble experiments to study the causes and consequences of polar amplification. We also encourage submissions from outside the PAMIP community, including contributions from observational, idealised modelling, and theoretical studies covering atmospheric, oceanic, and cryospheric perspectives on this topic. Research topics of interest include, but are not limited to: 1) the relative roles of remote versus local atmospheric and oceanic processes as well as cryospheric processes in driving polar amplification; 2) the physical pathways through which polar amplification influences lower-latitude weather and climate; 3) the ability of models to simulate these pathways and efforts to constrain the real world response; and 4) the relative influence of polar amplification compared to other climate drivers and across timescales from seasonal to multidecadal.

This session covers predictions of climate from seasonal to decadal timescales and their applications. With a time horizon from a few months up a few decades, such predictions are of major importance to society, and improving them presents an interesting scientific challenge. This session embraces advances in our understanding of the origins of seasonal to decadal predictability, as well as in improving the forecast skill and making the most of this information by developing and evaluating new applications and climate services.

The session welcomes contributions from dynamical as well as statistical predictions (including machine learning methods) and their combination. This includes predictions of climate phenomena, including extremes, from global to regional scales, and from seasonal to multi-decadal timescales ("seamless predictions"). The session also covers physical processes relevant to long-term predictability sources (e.g. ocean, cryosphere, or land) and predictions of large-scale atmospheric circulation anomalies associated to teleconnections as well as observational and emergent constraints on climate variability and predictability. Also relevant is the time-dependence of the predictive skill and windows of opportunity. Analysis of predictions in a multi-model framework, and ensemble forecast initialization and generation, including innovative ensemble approaches to minimize initialization shocks, are another focus of the session. The session pays 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.

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.

To address societal concerns over rising sea level and extreme events, understanding and quantifying the contributions behind these changes is key to anticipate potential impacts of sea level change on coastal communities and global economy. In this session, we address these challenges and we welcome contributions from the international sea level community that improve our knowledge of the past, present and future changes in global and regional sea level, extreme events and coastal impacts.
We focus on studies exploring the physical mechanisms for sea level rise and variability and the drivers of these changes, at any time scale (from high-frequency phenomena to paleo sea level). Investigations on linkages between variability in sea level, heat and freshwater content, ocean dynamics, land subsidence and mass exchanges between the land and the ocean associated with ice sheet and glacier mass loss and changes in the terrestrial water storage are welcome. Studies focusing on future sea level changes are also encouraged, as well as those discussing potential short-, medium-, and long-term impacts on coastal environments, as well as the global oceans.

Regional climate is often influenced by or connected to changes in remote locations, a phenomenon known as a teleconnection. Changes in the ocean, sea ice, atmosphere or land conditions in remote locations can trigger atmospheric or oceanic disturbances, which then propagate and influence the climate in one or multiple distant regions. These changes could be periodic modes of variability (such as ENSO, IOD, QBO, AMV, PDV etc.) or a response to anthropogenic forcing (such as the warming Western Tropical Pacific or the North Atlantic Warming Hole etc.). Fleshing out the teleconnections associated with such changes provides us with a clearer understanding of the variations in the climate of a particular region and may also provide a source of predictability. This session invites contributions that focus on this aspect of climate variability and yield new understanding on the origin, dynamics and predictive potential of teleconnections. The studies may be observational or modelling in nature and may be based on paleoclimatic time-scales, the historical period or future scenarios. Research on new methods to diagnose and understand teleconnections is also welcome.

Atmospheric circulation is unquestionably listed among the fundamental causes of weather and climate. The session is dedicated to all aspects of relationships between atmospheric circulation in different spatial scales and climate as well as environmental variables. Contributions concerning theoretical aspects of circulation classifications development and their applications in various tasks (climatological, and environmental), and different scales are particularly welcome as well as submissions on recent climate variability and change studied by tools of synoptic climatology.

Analysis of energy transfers between and within climate components has been at the core of many step changes in the understanding of the climate system. Large-scale atmospheric circulation, hydrological cycle and heat/moisture transports are tightly intertwined. Dynamics and radiative exchanges are linked at the global scale, through the net impact of cloud feedbacks, sea-ice albedo changes, surface absorption by vegetation.

In the Tropics, the zonal mean Hadley circulation determines meridional energy transports, while Rossby and planetary-scale waves modulate the energy exchanges carried by extratropical eddies. In the ocean, the role of Atlantic Meridional Overturning Circulation is essential for the heat budget of continental regions in the Northern Hemisphere: long-term oceanic and sea-ice variability is crucial to understand and predict the dynamics in high latitudes. Observational and model studies have indeed shown that the Arctic is very susceptible to climate change, and climate perturbations in the Arctic likely have wide-spread influence. High-latitude atmosphere, biosphere, oceans and cryosphere have experienced significant changes over the observational era. Hence, advancing the understanding of variability and change, governing mechanisms and global implications, improving predictions and projections of high latitude climate in both hemispheres is highly important for global society.

We invite submissions on the interplay between Earth’s energy exchanges and the general circulation through modeling, theory, and observations, on the forced response and natural variability of the general circulation, understanding present-day climate, past and future changes, impacts of global features and change on regional climate. This session also aims to improve knowledge and representation of the multi-scale mechanisms that control high-latitude climate variability and predictability in both hemispheres from sub-seasonal to multi-decadal and longer time scales. We thus invite contributions on the causes, mechanisms and climate feedbacks associated with the Arctic and Antarctic climate, ocean and sea ice change, including the potential links of the pronounced Arctic amplification to weather and climate outside the Arctic, and teleconnections of high latitude climate with lower latitude climate. We also aim to link climate variability, predictions and projections to potential ecosystem and socio-economic impacts and encourage submissions on this topic.

Simulations of past and future climate change remain limited by uncertainties, especially at spatial scales relevant for policy making. To provide more actionable climate information for risk assessments, climate storylines have become a popular approach to complement the probabilistic event attribution and climate projection. According to the latest IPCC-WG1 report, “the term storyline is used both in connection to scenarios or to describe plausible trajectories of weather and climate conditions or events”. Storylines are used to “explore uncertainties in climate change and natural climate variability, to develop and communicate integrated and context-relevant regional climate information, and to address issues with deep uncertainty, including low-likelihood, high-impact outcomes”.

Several flavours of storylines exist. One method attempts to attribute and project the climate signal in specific weather events in a climate model, using forcing and boundary conditions from different past, present, and possible future climates. This approach is used to quantify and explore thermodynamic climate effects while eliminating uncertain dynamical changes by constraining (nudging) the large-scale winds to reproduce the observed circulation. Another storyline method extracts possible and physically plausible (regional) climate change scenarios, conditional upon robustly simulated aspects of the climate system such as the large-scale dynamical response or the response of relevant climate modes, thereby disentangling the often-blurred multi-model mean response. Numerous storyline studies exist or are underway, ranging from global to regional (including pseudo-global-warming experiments) setups to local impacts, with both coupled or uncoupled (atmosphere or land-surface) models.

This session provides a forum to present and discuss the latest storyline-based climate research, and thereby to foster the exchange and collaboration in this fast-growing field. We invite contributions including but not limited to the approaches described above, using any analytical methods or modelling frameworks that seek to unravel climate change and, ultimately, provide actionable climate outcomes. Studies can range across spatial and temporal scales, and from fundamental considerations about the pros and cons of storyline approaches and how they relate to the probabilistic paradigm, to specific studies dealing with individual events, challenges, or other aspects of climate storylines.

Mediterranean climate regions of the world are located in transitional midlatitude zones like the Mediterranean basin area, western North America and small coastal areas of western South America, southern Africa and southern Australia. This transitional character makes them highly vulnerable to climate change. For all Mediterranean climate regions, the future holds high risks and uncertainty on biodiversity, aridity, ecosystems, and on the sustainability and the resilience of socio-economic systems. Innovative approaches to effective and sustainable climate adaptation and mitigation are, therefore, required. Understanding the past, characterizing the present and modeling the future become essential steps to estimate the risks, assess the impacts of climate change, and identify potential adaptation strategies.

This session intends to strengthen the exchanges among the communities studying the Mediterranean climate regions of the world and promote a multi-disciplinary approach in identifying and preparing shared solutions and practices. Studies focused on physical (including extremes, teleconnections, hydrological cycle) and biogeochemical (including biodiversity) aspects of Mediterranean climate regions, focusing on observed past changes and/or future climate projections, are welcome, as well as related social aspects including indigenous knowledge in mitigating climate risks. Analyses where multiple Mediterranean climate-type regions are considered and compared are highly welcome. Moreover, as a multidisciplinary MedCLIVAR session we encourage contributions from a broad range of disciplines and topics, e.g. dealing with: dynamics and processes of the climate system; sectoral impacts of climate change; climate change adaptation; innovative methods and approaches in climate science.

An increasing number of single model large ensemble simulations from Global Climate Models (GCM), Earth System Models (ESM), or Regional Climate Models (RCM) have been generated over 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 and study 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. Examples include topics ranging from climate dynamics, hydrology and biogeochemistry to 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.

This session hopes to bring together Climate Scientists, Mathematicians and Ecologists to answer key questions around the relationships between the variability and sensitivity of the Earth System and its subcomponents. In particular, this session will discuss observational constraints and tipping points for Earth System feedbacks.

State-of-the-art Earth System Models feature wide ranges of projected future change arising from uncertainties in both forcing factors (such as the climatic effects of anthropogenic aerosols) and feedbacks (such as those due to clouds or the carbon cycle). It is vital that we reduce these uncertainties to provide better information for climate change mitigation and adaptation. Constraints provide a method of reducing projection uncertainty, often by investigating relationships between temporal or spatial sensitivity and variability (such as Emergent Constraints). Tipping points are typically associated with some external forcing exceeding a critical level causing a system to transition abruptly to an alternative, and often less desirable, state. However, the role of temporal and spatial scales requires careful consideration given the possibilities of other tipping phenomena such as rate-induced tipping, overshoots and spatial cascades.

The aim of this session is to cover exciting new work on climate tipping points, and observational and emergent constraints on Earth System feedbacks, as well as to promote cross-fertilisation of ideas between these two important emerging topics in climate science. We invite contributions from a range of studies investigating variability and sensitivity of the Earth System, focussing on either constraining Earth System sensitivities or modelling/theoretical studies of tipping points.

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 interdivisional session --building bridges between the EGU divisions CL, AS, SSP, BG and GM-- had its first edition in 2004 and it 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, regional, and local 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 the submission of papers that integrate different disciplines and/or address the modelling of past, present and future climates.

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.

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. In particular, we welcome contributions making use of paleoclimate data and modelling to understand changes in the climate system dynamics and variability during the last glacial cycle, and the related implications for the future.

This session aims to provide a forum to present work on:
1. Characterization of climate dynamics using a variety of techniques (e.g. scaling and multifractal techniques and models, recurrence plots, variance analyses).

2. Proxy-system modelling to improve paleoclimate reconstructions and model-data comparisons

3. Relationship between mean state changes (e.g. glacial to interglacial or pre-industrial to present to future), and higher-order moments of relevant climate variables, including extreme-event occurrence and predictability.

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

5. Attribution of climate variability to internal and/or forced dynamics, including natural (e.g. volcanic and solar) and anthropogenic forcing changes.

6. Synchronization and pacing of glacial cycles through dynamical interaction of external forcing (e.g. orbital forcing) and internal variability.

7. Characterization of the probabilities of extremes, including linkage between slow climate variability and extreme event recurrence.

Members of the PAGES working group on Climate Variability Across Scales (CVAS) and the German Climate Modeling Initiative PalMod are particularly welcome.

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 taking a cross-disciplinary, system approach and focussing on emerging cryospheric, oceanic and biogeochemical processes and their links with land are particularly welcome.
The session supports the actions of the United Nations Decade of Ocean Science for Sustainable Development (2021-2030) towards addressing challenges for sustainable development in the Arctic and its diverse regions. We aim to promote discussions on the future plans for Arctic Ocean modelling and measurement strategies, and encourages submissions on the results from IPCC CMIP and the recent observational programs, such as the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC), which cosponsors this session.

Clouds play an important role in the Polar climate due to their interaction with radiation and their role in the hydrological cycle linking poleward water vapour transport with precipitation. Cloud and precipitation properties depend on the atmospheric dynamics and moisture sources and transport, as well as on aerosol particles, which can act as cloud condensation and ice nuclei. These processes are complex and are not well represented in the models. While measurements of cloud and precipitation microphysical properties in the Arctic and Antarctic regions are challenging, they are highly needed to evaluate and improve cloud processes representation in the models used for polar and global climate and cryosphere projections.

This session aims at bringing together researchers using observational and/or modeling approaches (at various scales) to improve our understanding of polar tropospheric clouds, precipitation, and related mechanisms and impacts. Contributions are invited on various relevant processes including (but not limited to):
- Drivers of cloud/precipitation microphysics at high latitudes,
- Sources of cloud nuclei both at local and long range,
- Linkages of polar clouds/precipitation to the moisture sources and transport, including including extreme transport events (e.g., atmospheric rivers, moisture intrusions),
- Relationship of moisture/cloud/precipitation processes to the atmospheric dynamics, ranging from synoptic and meso-scale processes to teleconnections and climate indices,
- Interactions between clouds and radiation, including impacts on the surface energy balance,
- Impacts that the clouds/precipitation in the Polar Regions have on the polar and global climate system, surface mass and energy balance, sea ice and ecosystems.

Papers including new methodologies specific to polar regions are encouraged, such as (i) improving polar cloud/precipitation parameterizations in atmospheric models, moisture transport events detection and attribution methods specifically in the high latitudes, and (ii) advancing observations of polar clouds and precipitation. We would like to emphasize collaborative observational and modeling activities, such as the Year of Polar Prediction (YOPP), Polar-CORDEX, the (AC)3 project on Arctic Amplification, MOSAiC and other measurement campaigns in the Arctic and Southern Ocean/Antarctica and encourage related contributions.

This session investigates mid-latitude to subtropical cyclones and storms on both hemispheres. We invite studies considering cyclones in different stages of their life cycles from the initial development, to large- and synoptic-scale conditions influencing their growth to a severe storm, up to their dissipation and related socioeconomic impacts. We also welcome studies investigating these weather systems and their climate controls in subtropical regions of both hemispheres.

Papers are welcome, which focus also on the diagnostic of observed past and recent trends, as well as on future storm development under changed climate conditions. This will include storm predictability studies on different scales. Finally, the session will also invite studies investigating impacts related to storms: Papers are welcome dealing with vulnerability, diagnostics of sensitive social and infrastructural categories and affected areas of risk for property damages. Which risk transfer mechanisms are currently used, depending on insured and economic losses? Which mechanisms (e.g. new reinsurance products) are already implemented or will be developed in order to adapt to future loss expectations?

This session welcomes papers on methodological developments in regional climate modelling, analysis of the performance of regional climate models (RCMs), use of RCMs for regional processes studies, paleoclimate and climate change projections, extreme event and impact assessment studies. The session also welcomes papers related to the CORDEX program, including both, the analysis of CORDEX-CORE experiments and simulations within the framework of different CORDEX Flagship Pilot Studies. Finally, abstracts are encouraged on the use of RCMs at both hydrostatic and convection-permitting ultra-high resolutions.

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.
Radiocarbon (14C) in particular is a key environmental tracer that can be widely applied in geochronology, environmental, and climate sciences. It is an invaluable tool to understand the global carbon cycle, as it can be used to trace the transfer of carbon between the atmosphere and other reservoirs, e.g., soils, oceans, and the geosphere, and to understand the impact of anthropogenic perturbations on these reservoirs.

With this session, we aim at bringing together an interdisciplinary group of researchers focused on dating and understanding climate archives of the Quaternary Period. Our session will focus on the application of geochronometers on one hand, as well as on the use of radiocarbon from natural reservoirs and archives that improve our understanding of the carbon cycle. In particular, we look forward to discussing (1) experimental and analytical advances (e.g. in sample preparation and measurement techniques); (2) methods that reduce, quantify and express dating uncertainties in any dating method, including high-resolution radiocarbon approaches; (3) new insights into the global carbon cycle, e.g., storage times in soils, sediment dispersal, ocean circulation, or carbon transfer between reservoirs; (4) general geochronological applications such as long-term landscape evolution, rates of geomorphological processes, and chronologies for records of climate change.

A big challenge in Earth system science is providing reliable climate predictions on sub-seasonal, seasonal, decadal and longer timescales. Resulting data can potentially be translated into climate information for better assessment of global and regional climate-related risks. Latest developments and progress in climate forecasting on different timescales will be discussed and evaluated, including predictions for different time horizons from dynamical ensemble and statistical/empirical forecast systems, and the aspects required for their application: forecast quality assessment, multi-model combination, bias adjustment, downscaling, etc. Contributions on initialization methods that use observations from different Earth system components, on assessing and mitigating impacts of model errors on skill and on ensemble methods will be included, much as 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 development of early warning systems.
Another focus is on the use of operational climate predictions (C3S, NMME, S2S), results from CMIP5-CMIP6 decadal prediction experiments, and climate-prediction research and application projects. Since an important part of climate forecast is to apply appropriate downscaling methods -dynamic, statistical or a combination- to generate time series and fields with appropriate spatial or temporal resolution, this will be covered by the session, which aims to bring together scientists from all geoscientific disciplines working on the prediction and application problems. Following the new WCRP strategic plan for 2019-2029, prediction enhancements are also sought that embrace climate forecasting from an Earth system science perspective, including study of coupled processes between atmosphere, land, ocean and sea-ice components, and the impacts of coupling and feedbacks in physical, chemical, biological and human dimensions including migration. On migration, the focus is on migratory species or those that are forced to migrate due to a change in the frequency and severity of climatic disturbances or human intervention, i.e. land use land cover change. This part of the session is for researchers working on terrestrial, marine or freshwater species and studies covering all aspects of migration including trait and behavioral changes as a response to sudden or gradual environmental changes, at all temporal scales.

Homogeneous long-term data records (i.e., well calibrated quality-controlled 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 requires harmonized data records (i.e., well calibrated quality-controlled data that maintained the unique nature of each sensor). Climate data records need to be screened and cleared from artificial non-climatic temporal and/or spatial effects, such as gradual degradation of instruments, jumps due to instruments changes, jumps due to observation practices changes, or jumps due to changes of station location and exposure. The magnitude and uncertainty of these gradual and/or abrupt changes determines their suitability for climate trend analyses. Therefore, data intended for applications, such as making a realistic and reliable assessment of historical climate trends and variability, require consistently homogenized and/or harmonized data records including measurement uncertainties.

The above described artificial non-climatic effects influence the quality of different Essential Climate Variables (ECVs), including atmospheric (e.g., air temperature, precipitation, wind speed), oceanic (e.g., sea surface temperature), and terrestrial (e.g., albedo, snow cover) variables. Our session calls for contributions, using data records from i) in-situ observing networks, ii) satellite observing systems, and or iii) climate/earth-system model simulations based data records, on the:

• Calibration, quality control, homogenization/harmonization and validation of either Fundamental Climate Data Records (FCDRs) and/or Essential Climate Variables data records (CDRs).

• 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. In particular, we encourage wind studies dealing with the observed slowdown (termed “stilling”; last 30-50 years) and recent recovery (since ~2013) of near-surface winds.