Union-wide
Community-led
Inter- and Transdisciplinary Sessions
Disciplinary sessions

CL – Climate: Past, Present & Future

Programme Group Chair: Kerstin Treydte

MAL14-CL
Hans Oeschger Medal Lecture by Heather Marie Stoll
Convener: Kerstin Treydte
MAL22-CL
Milutin Milanković Medal Lecture by Zhengyu Liu
Convener: Kerstin Treydte
MAL36-CL
CL Division Outstanding ECS Award Lecture by Kai Kornhuber
Convener: Kerstin Treydte

CL0 – Inter- and Transdisciplinary Sessions

Sub-Programme Group Scientific Officer: Kerstin Treydte

ITS2.1/CL0.1 EDI

High-impact climate and weather events typically result from the interaction of multiple climate and weather drivers, as well as vulnerability and exposure, across various spatial and temporal scales. Such compound events often cause more severe socio-economic impacts than single-hazard events, rendering traditional univariate extreme event analyses and risk assessment techniques insufficient. It is, therefore, crucial to develop new methodologies that account for the possible interaction of multiple physical and societal drivers when analysing high-impact events under present and future conditions. Despite the considerable attention from the scientific community and stakeholders in recent years, several challenges and topics must still be addressed comprehensively.

These include: (1) identifying the compounding drivers, including physical drivers (e.g., modes of variability) and/or drivers of vulnerability and exposure, of the most impactful events; (2) Developing methods for defining compound event boundaries, i.e. legitimate the ‘cut-offs’ in the considered number of hazard types to ultimately disentangle enough information for decision-making; (3) Understanding whether and how often novel compound events, including record-shattering events, will emerge in the future; (4) Explicitly addressing and communicating uncertainties in present-day and future assessments (e.g., via climate storylines/scenarios); (5) Disentangling the contribution of climate change in recently observed events and future projections; (6) Employing novel Single Model Initial-condition Large Ensemble simulations from climate models, which provide hundreds to thousands of years of weather, to better study compound events. (7) Developing novel statistical methods (e.g., machine learning, artificial intelligence, and climate model emulators) for compound events; (8) Assessing the weather forecast skill for compound events at different temporal scales; (9) Evaluating the performance of novel statistical methods, climate and impact models, in representing compound events and developing novel methods for reducing uncertainties (e.g., multivariate bias correction and emergent constraints); and (10) engaging with stakeholders to ensure the relevance of the aforementioned analyses.

We invite presentations on all aspects of compound events, including but not limited to the topics and research challenges described above.

Solicited authors:
Laura Suarez-Gutierrez
Convener: Pauline Rivoire | Co-conveners: Judith ClaassenECSECS, Emanuele Bevacqua, Anaïs CouasnonECSECS, Yang Chen, Michele Ronco
ITS1.6/CL0.3 EDI

Earth System Models (ESMs), climate forcing, and Earth system reconstructions are crucial for understanding climate dynamics. However, disparities in responses to forcing agents, system coupling - particularly across CMIP - as well as the integration of reconstructions, present significant challenges. This session combines insights from deep-time Earth system reconstructions with cutting-edge climate modeling to enhance our understanding of past, present, and future climate change. We highlight the role of anthropogenic and natural forcings, the importance of addressing model uncertainties in CMIP and beyond, opportunities to develop next-generation digital twins of our planet, and present CMIP7 forcings. This session features contributions that span the following themes:

1. Earth System Reconstructions and Digital Twins
- Integrating paleogeographic data and advanced modeling (e.g., machine learning) to reveal past environmental changes and major Earth system transitions.
- Building digital twins of the planet by fusing diverse datasets and numerical models, emphasizing open, community-driven approaches.

2. Anthropogenic and Natural Forcing for CMIP6, CMIP7, and beyond
- Developing and evaluating historical and future time series of climate drivers (e.g., greenhouse gases, aerosols, land-use changes).
- Investigating how changes in forcing propagate through the climate system, using both observational data and idealized or multi-model experiments (CMIP6, CMIP7, etc.).

3. Model Disparities and Uncertainty
- Identifying the causes of divergent outcomes within CMIP ensembles, including internal variability, parameterization, external forcings, and ESM architectures.
- Employing reduced-complexity models and emulators to capture underexplored regions of uncertainty and guide more robust climate projections.

4. Critical Model Development and Impact Research
- Refining ESMs to reduce uncertainties and improve model performance, with emphasis on interdisciplinary approaches.
- Addressing regional-scale challenges in using CMIP outputs for impact studies, ensuring that policymakers and non-experts can effectively interpret climate projections.

We encourage submissions that bridge these topics, highlight open research and interdisciplinary collaboration, and showcase the work of early career researchers.

AGU and WMO
Convener: Lina TeckentrupECSECS | Co-conveners: Haipeng LiECSECS, Jarmo KikstraECSECS, Guillaume Dupont-Nivet, Camilla MathisonECSECS, Christopher Smith, Alexander J. WinklerECSECS
ITS2.6/CL0.4 EDI

As climate change causes impacts from weather extremes to increase around the world, decision makers in government and industry are increasingly required to address changes to climate hazards when considering, disclosing, and acting to mitigate risks. Given that risk is the nexus of hazard, vulnerability, and exposure, a complete understanding of risk requires an interdisciplinary approach with input from experts in changes to all three of these pillars. In this session we address specifically those risks related to extreme weather events, including temperature, precipitation, and wind extremes, with a focus on interdisciplinary approaches that bridge the gap between the physical sciences and decision makers. We invite contributions from interdisciplinary teams working to address these challenges, as well as from those working in single disciplines but seeking to make interdisciplinary connections. Topics of interest include storyline approaches in which societal challenges are considered alongside physical climate risks; addressing knowledge gaps in physical hazard understanding when providing information to decision makers; issues related to the financial and insurance sectors’ responses to extreme weather events; impact-based forecasting as a tool for risk understanding; and studies of early-warning systems and associated decision making.

Solicited authors:
Jana Sillmann
Convener: Timothy Raupach | Co-conveners: Ben Newell, Tanya Fiedler, Olivia Martius, Matthias RoethlisbergerECSECS, Dorothea Frank, Vitus BensonECSECS
ITS2.4/CL0.5 EDI | PICO

The interconnection between climate, environment, and health is evident, with climate change posing significant threats to human welfare. As global temperature rise, extreme weather events such as heatwaves, floods, hurricanes, and droughts, directly and indirectly impact public health, alongside environmental exposures like air pollution. Climate and land use changes can influence the spread of vector-borne diseases such as malaria and increase the risk of waterborne illnesses. Additionally, climate change may result in severe wildfires and episodes of air pollution.
Addressing these complex challenges requires fostering interdisciplinary collaboration among climate researchers, epidemiologists, public health researchers, and social scientists, which is the primary focus of this session. The goal is to create a platform for presenting the latest innovations in using remote sensing and other large datasets to characterize exposures relevant to human health, especially in data-limited regions. The session encompasses various topics, including satellite data applications in human health, planetary epidemiology, risk mapping of infectious diseases, exposure mapping of heat and air pollution to quantify their impacts on human health, health co-benefits of mitigation actions, and the use of machine learning and AI for climate and health applications. The session emphasizes the examination of historical exposure-health outcome relationships, forecasts for the near future, and changes under progressive climate change.

Solicited authors:
Silvana Di Sabatino
Convener: Irena Kaspar-Ott | Co-conveners: Sourangsu Chowdhury, Elke Hertig, Sagnik Dey
ITS1.1/CL0.9 EDI

Machine learning (ML) is currently transforming data analysis and modelling of the Earth system. While statistical and data-driven models have been used for a long time, recent advances in machine learning now allow for encoding non-linear, spatio-temporal relationships robustly without sacrificing interpretability. This has the potential to accelerate climate science, by providing new physics-based modelling approaches; improving our understanding of the underlying processes; reducing and better quantifying climate signals, variability, and uncertainty; and even making predictions directly from observations across different spatio-temporal scales. The limitations of machine learning methods need to also be considered, such as requiring, in general, rather large training datasets, data leakage, and/or poor generalisation abilities, so that methods are applied where they are fit for purpose and add value.

This session aims to provide a venue to present the latest progress in the use of ML applied to all aspects of climate science and we welcome abstracts focussed on, but not limited to:
- Causal discovery and inference: causal impact assessment, interventions, counterfactual analysis
- Learning (causal) process, equations, and feature representations in observations or across models and observations
- Hybrid models (physically informed ML, emulation, data-model integration)
- Novel detection and attribution approaches, including for extreme events
- Probabilistic modelling and uncertainty quantification
- Super-resolution for climate downscaling
- Explainable AI applications to climate data science and climate modelling
- Distributional robustness, transfer learning and/or out-of-distribution generalisation tasks in climate science

Solicited authors:
Laura Mansfield
Convener: Duncan Watson-Parris | Co-conveners: Peer Nowack, Tom BeuclerECSECS, Gustau Camps-Valls, Paula HarderECSECS
ITS1.4/CL0.10 EDI

Machine learning (ML) is being used throughout the geophysical sciences with a wide variety of applications. Advances in big data, deep learning, and other areas of artificial intelligence (AI) have opened up a number of new approaches to traditional problems.

Many fields (climate, ocean, NWP, space weather etc.) make use of large numerical models and are now seeking to enhance these by combining them with scientific ML/AI techniques. Examples include ML emulation of computationally intensive processes, data-driven parameterisations for sub-grid processes, ML assisted calibration and uncertainty quantification of parameters, amongst other applications.

Doing this brings a number of unique challenges, however, including but not limited to:
- enforcing physical compatibility and conservation laws, and incorporating physical intuition,
- ensuring numerical stability,
- coupling of numerical models to ML frameworks and language interoperation,
- handling computer architectures and data transfer,
- adaptation/generalisation to different models/resolutions/climatologies,
- explaining, understanding, and evaluating model performance and biases.
- quantifying uncertainties and their sources
- tuning of physical or ML parameters after coupling to numerical models (derivative-free optimisation, Bayesian optimisation, ensemble Kalman methods, etc.)

Addressing these requires knowledge of several areas and builds on advances already made in domain science, numerical simulation, machine learning, high performance computing, data assimilation etc.

We solicit talks that address any topics relating to the above. Anyone working to combine machine learning techniques with numerical modelling is encouraged to participate in this session.

Convener: Jack AtkinsonECSECS | Co-conveners: Will Chapman, Laura MansfieldECSECS
ITS4.6/CL0.11

Climate change and environmental degradation constitute a growing threat to the stability of societal and economical systems. The observed and anticipated escalation in the frequency and intensity of extreme weather events under future emission scenarios, combined with the projected long-term shifts in climate patterns and consequential impacts on biodiversity, have the potential to significantly affect specific sectors such as insurance and finance leading to significant economic damages on a local to global scale.

In recognition of this challenge climate risk assessments have experienced amplified attention in both the academic and private spheres, leading to initiatives such as the ‘Network for Greening the Financial Sector’ (NGFS) and the ‘Task Force on Climate-Related Financial Disclosure’ (TCFD) and a growth in climate risk services aiming at setting standards and frameworks as well as the provision of comprehensive climate impact information for the private sector and financial institutions.

The need for more adequate risk assessment poses new academic challenges: the accurate representing extreme events and their compounding and cascading effects on high spatial resolution and the integration of non-linearities associated with tipping elements in the climate system to avoid an underestimation of physical climate risks.

Therefore, providing a platform to foster interactions between scientists, economists and financial experts is urgently needed. With the goal of facilitating such dialogue, this session aims at providing a platform for actors from academia and the private sector to exchange information on strategies for assessing climate risk.

The session is organised under three main pillars:
-Physical Climate Risks: Trends, Processes and Modelling
-Identifying and Managing Climate Risks
-Quantifying Damages and Impacts from Climate Risks

We encourage submissions on:
Innovative climate risk modeling for
-Chronic and Acute Climate Risks
-Compound Events and Cascading Impacts
-Model Evaluation of Extreme weather events
AI and Machine learning frameworks for
-Bias adjustment Methods
-Downscaling Methods
-Fast climate models and emulators
Climate hazard indicators and their projections for specific sectors:
-Food, Energy, Insurance, Real Estate
-Supply chains
Impact data collection and empirical damage assessments
Global and local damage functions
Climate – Nature nexus

Solicited authors:
Nicholas Leach
Convener: Kai Kornhuber | Co-conveners: Nicola Ranger, Alessio Ciullo, Andrej Ceglar, Jana Sillmann, Maximilian KotzECSECS
ITS2.3/CL0.12 EDI | PICO

Over the past 50 years, climate extremes have caused more than 2 million deaths and an estimated $3.64 trillion in economic losses worldwide. Beyond these direct impacts, the effects on population health have become an urgent concern. Research has highlighted far-reaching consequences, particularly in terms of excess mortality and morbidity associated with cardiovascular and respiratory diseases, associated with climate extremes. The burden of these health impacts is not evenly distributed. Socioeconomic, demographic, and geographical factors heavily influence vulnerability, leading to significant disparities in health outcomes across different populations. For example, marginalized and disadvantaged groups, including the elderly, children, individuals with pre-existing health conditions, and residents of low-income or geographically vulnerable regions bear a disproportionate share of the health burden. Intersectionality plays a key role in this disparity; including overlapping social factors such as race, gender, age, and income interact to intensify existing vulnerabilities to climate extremes, climatic factors and health inequalities. This differential vulnerability underscores the critical link between climate justice and population health, emphasizing the need to address inequalities to strengthen resilience and mitigate population health impacts of climate extremes. This session is a contribution to the Swedish centre for impacts of climate extremes (climes), and welcomes all contributions that explore the complex impacts of climate extremes on population health, including studies on how intersecting socioeconomic, demographic, and geographical factors shape vulnerability.

Convener: Elena Raffetti | Co-conveners: Gabriele Messori, Antonio Gasparrini, Stefan Döring, Maurizio Mazzoleni
ITS3.1/CL0.14 EDI

Environmental issues are not only ecological but also societal and cultural. To address them effectively, we need to understand how human societies interact with the environment. This session highlights the importance of social science in environmental research and vice versa, and invites contributions that explore how interdisciplinary collaboration can lead to innovative and sustainable solutions. We welcome scientists from all disciplines of environmental and social sciences, data analysts, methodologists, and metadata experts to share their insights, case studies, and challenges. We aim to foster meaningful discussions and exchange of ideas across academic groups, research infrastructures, the private sector, and policy makers. By integrating the expertise of social scientists with environmental research, we can develop a more comprehensive and holistic understanding of environmental problems leading to pathways for viable climate action plans and supporting policies. Let's work together to contribute to a more sustainable relationship between people and the environment.
Topics may include, but are not limited to:
– Climate action plans and solutions for green and sustainable cities
– Cultural heritage and environmental sustainability
– Environmental policy and governance
– Air quality and climate indicators
– Sustainable agriculture and land use
– Biodiversity conservation and ecosystem services
– Climate adaptation and resilience
– Development of resilient communities through disaster risk reduction
– Citizen and participatory science and public engagement
– Best practice methodologies for specific use cases
– Metadata standards for integration of data from different research domains
– Project reports or infrastructure requirements related to multidisciplinary use cases

Our solicited speaker is Bonnie Wolff-Boenisch, CEO of CESSDA ERIC. Bonnie has 25 years of work experience in research and infrastructures, management and advocacy across different cultures, countries and disciplines. She is a member of Scientific Advisory Boards in Germany, Italy, France and the US, and has a PhD in Isotope Geochemistry from the Max-Planck Institute in Mainz, Germany.

Solicited authors:
Bonnie Wolff-Boenisch
AGU and ICOS
Convener: Hilde Orten | Co-conveners: Claudio D'Onofrio, Hannah Clark, Angeliki Adamaki, Solmaz MohadjerECSECS
ITS2.2/CL0.16

Life on earth evolved through various geological ages in close interaction with the climate system. While the past climate changes have played a crucial role in shaping the terrestrial life distribution by modifying habitat and resource availability, modern humans have compounded these impacts by inducing a dramatic shift in the global biodiversity patterns. The evolutionary history of terrestrial life is characterized by migrations, adaptations, speciation and mass extinctions, with constant restructuring of the global ecosystem. Understanding the complex linkage between climate and terrestrial life forms is crucial in managing the present environmental challenges and developing effective conservation strategies for addressing potential biodiversity crisis in the future.

This session aims at bringing together multidisciplinary research on how climate has impacted and will impact terrestrial life forms and ecosystem structure in the past, present and future.

Topics of interest include,
- Mass extinctions in the past
- Climate and human influences on global biodiversity patterns
- Climate-driven species migrations
- Genetic diversification and speciation
- Vegetation dynamics and biome shifts
- Habitat degradation and effects on species distribution
- Species interactions and changes in ecosystem composition
- Climate-ecosystem modelling
- Conservation ecology

This multidisciplinary session at the nexus between climate change research and ecology will provide an opportunity for researchers to interact, forge new collaborations and exchange knowledge.

Convener: Thushara VenugopalECSECS | Co-convener: Jiaoyang Ruan

CL1.1 – Past Climate - Deep Time

Sub-Programme Group Scientific Officers: Jan-Berend Stuut, Elisabeth Dietze

CL1.1.1 EDI

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 and carbon cycle 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 communities. This session invites work on deep-time climate, Earth System model simulations and proxy-based reconstructions from the Cambrian to the Pliocene. We especially encourage submissions featuring palaeoenvironmental reconstructions, palaeoclimate and carbon cycle modelling, and the integration of CO2 and (hydro)climate proxies and models of any complexity.

Solicited authors:
Yige Zhang,Trond H. Torsvik,Richard Stockey
Co-organized by BG5/SSP2
Convener: Jean-Baptiste Ladant | Co-conveners: Hana JurikovaECSECS, Xinping Liang, Yonggang Liu, Anta-Clarisse Sarr, Hui Tian, Pam VervoortECSECS
CL1.1.3 EDI

This session aims to bring together proxy-based, theoretical and/or modelling studies focused on both regional and global climate responses to astronomical forcing at different time scales throughout the history of Earth.

We invite contributions which discuss possible connections between the astronomical forcing and transitions in the dynamics of the Earth system, including global: extinctions, anoxia, global glaciations, regime changes, and more regional events. We aim at bringing together contributions which are either based on observations, on theoretical arguments, or both. We welcome submissions which explore the climate system response to orbital forcing, and that analyse the stability of these relationships under different climate regimes or across evolving climate states. This includes the Cenozoic (e.g. mid Pleistocene transition, Pliocene-Pleistocene transition, Miocene vs Pliocene), old the other periods of the Phaneorozoic and before. We also particularly welcome submissions which explore the effects of astronomical forcing on expression and amplification of millennial variability.

Solicited authors:
Pam Vervoort
Convener: Michel Crucifix | Co-conveners: Anne-Christine Da Silva, Stefanie Kaboth-BahrECSECS, Ulfers ArneECSECS, Christian Zeeden
TS2.8 EDI

The Neoproterozoic Era is known for rapid continental scale movements manifested by at least two major supercontinent assemblies: Rodinia and Gondwana. It is believed that the early-middle Proterozoic continental fragments grew to form Rodinia by a series of collisions at ~1000 Ma and broke up in stages from 1000 to 520 Ma. Before Rodinia had completely broken up, some of its segments had already begun to form Gondwana, which assembled completely by ~500 Ma.
The Neoproterozoic Era sandwiched between the Grenvillian and Pan-African orogenic activities, experienced dramatic changes in the global environment and the development and fragmentation of supercontinents. Significant crustal readjustments from Rodinia to Gondwana during the Neoproterozioc era (1000-542 Ma) have been reported. This interval of rapid plate configuration changes is often considered an important factor for the preceding biological changes. Therefore, it’s crucial to understand the paleogeographic distribution of cratons during the Neoproterozoic Era to understand the dawn of complex life. Despite significant developments, a major gap in our understanding exists between the breakup of Rodinia and the assembly of Gondwana.
This session invites Earth scientists to explore and investigate the 1100-500 million years ago interval to illuminate the intricate dynamics of this transformative era.

Solicited authors:
Thomas Gernon
Co-organized by CL1.1
Convener: Sadhana Chatterjee | Co-conveners: Fabricio Caxito, Antoine Triantafyllou, Devsamridhi AroraECSECS, Kaushik Das
BG5.3 EDI

This session aims to bring together a diverse group of scientists who are interested in how life and planetary processes have co-evolved over geological time. This includes studies of how paleoenvironments have contributed to biological evolution and vice versa, linking fossil records to paleo-Earth processes and the influence of tectonic and magmatic processes on the evolution of climate and life. As an inherently multi-disciplinary subject, we aspire to better understand the complex coupling of biogeochemical cycles and life, the links between mass extinctions and their causal geological events, how fossil records shed light on ecosystem drivers over deep time, and how tectono-geomorphic processes impact biodiversity patterns at global or local scales. We aim to understand our planet and its biosphere through both observation- and modelling-based studies. We also invite contributions on general exoplanet-life co-evolution.

This session is co-organized by COST Action CA23150 - pan-EUROpean BIoGeodynamics network (EUROBIG)

Solicited authors:
Taras Gerya,Sean Willett
Co-organized by CL1.1/GD3/GM4/PS6, co-sponsored by pan-EUROpean BIoGeodynamics network (EUROBIG)
Convener: Julian RoggerECSECS | Co-conveners: Jack LongmanECSECS, Jun ShenECSECS, Yaquan ChangECSECS, Attila Balázs, Zhen XuECSECS, Fred BowyerECSECS
GD3.2 EDI | PICO

The first half of Earth’s history (Hadean to Paleoproterozoic) laid the foundations for the planet we know today. But how and why it differed and how and why it evolved remain enduring questions.
In this session, we encourage the presentation of new approaches that improve our understanding on the formation, structure, and evolution of the early Earth ranging from the mantle and lithosphere to the atmosphere, oceans and biosphere, and interactions between these reservoirs.
This session aims to bring together scientists from a large range of disciplines to provide an interdisciplinary and comprehensive overview of the field. This includes, but is not limited to, fields such as early mantle dynamics, the formation, evolution and destruction of the early crust and lithosphere, early surface environments and the evolution of the early biosphere, mineral deposits, and how possible tectonic regimes impacted across the early Earth system.

Co-organized by BG7/CL1.1/GMPV5/TS6
Convener: Ria FischerECSECS | Co-conveners: Jeroen van Hunen, Ezequiel José Estremina Carneiro Brandão Ferreira, Bing Xia, Peter Cawood, Desiree Roerdink

CL1.2 – Past Climate - Last ~2.6 Ma

Sub-Programme Group Scientific Officers: Jan-Berend Stuut, Carole Nehme

CL1.2.1 EDI

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.

Solicited authors:
Guobao Xu
Co-organized by BG3
Convener: Elisabet Martinez-SanchoECSECS | Co-conveners: Kerstin Treydte, Annemarie Eckes-Shephard, Jernej JevšenakECSECS, Pieter Zuidema
CL1.2.2 EDI

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.

Solicited authors:
Jason Smerdon
Co-sponsored by PAGES 2k
Convener: Andrea Seim | Co-conveners: Daniel BoatengECSECS, Jun HuECSECS, Hugo Beltrami, Stefan Bronnimann
CL1.2.3

Speleothems are key terrestrial archives of regional to global paleoclimatic and paleoenvironmental changes on sub-seasonal to orbital scales. They provide high temporally resolved records which can be accurately and precisely dated using a variety of proxies such as stable O and C isotopes and trace elements. Recent efforts have seen the rise in more non-traditional proxies such as fluid inclusion water isotopes, organic biomarkers, pollen, dead carbon fraction etc.. This advancement towards quantitative reconstructions of past precipitation, temperature, or other environmental variables and climate patterns, are key variables for data-model comparisons and evaluation. Beyond this, caves and karst areas additionally host an enormous suite of other valuable archives such as cave ice, cryogenic carbonates, clastic sediments, tufa, or travertine sequences which complement the terrestrial palaeorecord, and are often associated with important fossils or archaeological findings.
This session aims to integrate recent developments in the field, and invites submissions from a broad range of cave- and karst-related studies from orbital to sub-seasonal timescales.
In particular we welcome contributions from:
(1) (quantitative) reconstructions of past climatic and environmental variables to reconstruct precipitation, vegetation, fire frequency, temperature etc. across different climate zones,
(2) field- and lab-based developments of process-based methods to improve our application of proxy variables,
(3) process and proxy-system model studies as well as integrated research developing and using databases such as SISAL (Speleothem Isotope Synthesis and AnaLysis).
We further welcome advancements in related and/or interdisciplinary areas, which pave the way towards robust (quantitative) interpretations of proxy time series, improve the understanding of proxy-relevant processes, or enable regional-to-global and seasonal-to-orbital scale analyses of the relationships between proxies and environmental parameters. 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.

Solicited authors:
Jessica Oster
Co-organized by BG5/SSP2, co-sponsored by PAGES
Convener: Sophie Warken | Co-conveners: Laura EndresECSECS, Anika DonnerECSECS, Rieneke WeijECSECS
CL1.2.5 EDI

A key limitation of observational climate data is the length of the instrumental record. Palaeo-archives offer solutions to extend the instrumental data framework, as these record a variety of climatic parameters. The investigation of these natural archives can reveal at (sub)annual, multi-decadal and centennial resolutions the scale, range and amplitude of climate variability, as well as extreme and rare events poorly sampled up to now. Increasingly, Holocene climates (alongside other geological periods) are shown to be dynamic with the detection of low frequency climate variability operating as individual episodes and as recurring modes (e.g. NAO, ENSO, AMV, PDV), both altering temperature and precipitation patterns spatiotemporally. Low frequency climate variability during the Holocene can be related to long term changes in orbital forcing, solar forcing and volcanism with associated feedbacks, but also to internal variability from changes to ocean and atmospheric circulation patterns.

It is only through the proxy detection, and data assimilation, of the complete range of climate variability that we can begin feed this learnt climate data into climate models to not only better understand the mechanisms of variability during different time periods but also to test climate model capability to reproduce this low frequency climate variability. The detection of the complete range of Holocene climate variability, and by extension older time periods, and validation of both proxies and models is therefore important for near-term and multi-decadal climate predictions and projections. These analyses are crucial both scientifically, but also societally to underpin climate policy and climate services, given projected climate change.

This session welcomes:
- Traditional and novel approaches to reconstructing Earth’s climate at (sub)annual to centennial scales.
- Transient climate model simulations of climate and the evaluation of climate models for future climate projection.
- Methodological advancements in modelling, including innovations in isotope-enabled climate models, proxy system models, data assimilation and machine learning techniques that aim to reconcile differences in temporal variability and spatial representation between models and proxies.
- Inter-proxy and climate model validation approaches to test the robustness of climate reconstructions.
-Efforts to use resolved climate data as a tool for climate services and policy.

Convener: Ash AbrookECSECS | Co-conveners: Josefine AxelssonECSECS, Raphael HébertECSECS, Kira Rehfeld, Paul LincolnECSECS, Laura BoyallECSECS, Amen Al Yaari
CL1.2.7 EDI

The half-century since the first deep ice core drilling at Camp Century, Greenland, has seen increased spatial coverage of polar ice cores, as well as extensive development in methods of ice sample extraction, analysis and interpretation. Growth and innovation continue as we address pressing scientific questions surrounding past climate dynamics, environmental variability and glaciological phenomena. New challenges include the retrieval of old, highly thinned ice, interpretation of altered chemical signals, and the integration of chemical proxies into earth system models. We invite contributions reporting the state-of-the-art in ice coring science, 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, proxy system modelling and related earth system modelling. We encourage submissions from early career researchers from across the broad international ice core science community. Contributions from on-going projects focusing on old and/or deep ice including, Green2Ice, COLDEX and Beyond EPICA Oldest Ice are very welcome.

Solicited authors:
Carlo Barbante
Co-organized by CR6
Convener: Rachael Rhodes | Co-conveners: Lison SoussaintjeanECSECS, Thomas Blunier, Nicolas StollECSECS, Daniel Baggenstos
CL1.2.10 EDI

Understanding the past climate and especially the associated feedback mechanisms involving clouds, vegetation, sea ice, ice sheets, ocean circulation, and the carbon cycle—such as those that substantially shaped the amplitude and timing of Quaternary deglaciations and the preceding glacial periods, as well as abrupt millennial-scale climate transitions during the last glacial period (the so-called Dansgaard–Oeschger, or ‘D-O’ events)—are crucial for constraining the future climate.

Many uncertainties remain about the role of these feedbacks and the associated interactions between different Earth system elements. This session will provide an opportunity to assess recent progress in documenting and understanding glacial-interglacial transitions and abrupt climate (including D-O events) events, and to evaluate the state of knowledge about model behaviour during these periods of major Earth system change.

We especially focus on the role of sea ice in abrupt climate shifts, but also include studies that explore both colder and warmer-than-modern climate states. Especially, we include proxy studies, such as IP25 from sediment cores or halogens from ice cores, covering past climatic periods that refine existing records and/or generate new data to advance the understanding of sea ice processes and associated climate changes, thereby enhancing or constraining cutting-edge climate models.

We encourage studies based on climate proxy data, and those using numerical models to submit abstracts with the aim of facilitating a comprehensive overview of processes, feedbacks, and tipping points during glacials and deglaciations; and particularly welcome CMIP-PMIP-relevant contributions.

Solicited authors:
Masa Kageyama,Sam Sherriff-Tadano
Convener: Irene Malmierca Vallet | Co-conveners: Andrea Spolaor, Erin McClymont, Helle Astrid Kjær, Louise Sime, Heather Stoll, Ruza Ivanovic
CL1.2.12 EDI

Quaternary climate variability is characterised by changes in the carbon cycle on all timescales from seasonal to orbital (glacial-interglacial cycles), manifesting in large variations in the atmospheric CO2 concentrations. Studying the natural carbon cycle variability is essential to address the current challenges of climate change. However, interpreting past changes remains difficult due to the complex and poorly understood interactions between the different reservoirs of the climate system (ocean, atmosphere, biosphere, lithosphere, cryosphere) and their impacts on the carbon cycle. Among these are impacts of changes in oceanic circulation and productivity, and interactions between vegetation composition, wildfire regimes and atmospheric conditions. Paleo-environmental proxy records and Earth system models provide insights into natural variations in atmosphere-carbon exchange, ocean carbon storage, and vegetation-fire-climate interactions. In particular, they can inform on changed dynamics due to major climatic transitions during the Quaternary, and on changes due to anthropogenic climate change and human land management.

We invite contributions that focus on vegetation, wildfire and ocean dynamics during the Quaternary and their interactions with climate to understand changes in the continental and oceanic carbon cycle. This includes: (a) regional and global-scale reconstructions of fire regimes and vegetation cover from paleo-environmental data, (b) multi-tracer analyses (e.g., micropaleontology, geochemistry) of marine sediment cores to reconstruct variations in carbon stocks and fluxes between the atmosphere and the ocean, (c) the development and application of innovative proxies and archives, (d) Earth system model simulations and comparisons with proxy records, and (e) studies that can inform future land management policies.

Solicited authors:
Matthew Adeleye
Co-organized by BG5
Convener: Yuval BurstynECSECS | Co-conveners: Thomas ExtierECSECS, Nils WeitzelECSECS, Stephanie Desprat, Jessica Oster, Nicolas Pige, Micheline CampbellECSECS
CL1.2.13 EDI

Understanding the interplay between stratigraphy, sedimentology, and paleoclimate across various timescales is essential for reconstructing Earth’s history, and its relevance for i.a. human evolution, migration, and cultural innovation. Conventional approaches, such as sedimentological and stratigraphic analysis of outcrop-, lacustrine , and marine records, provide a foundational framework for understanding long-term paleoclimatic shifts and its link to archaeological and paleoanthropological contexts.
However, investigating processes and interactions on human-relevant timescales (seasonal to multi-decadal) requires methods providing high temporal and possibly spatial resolution. Recent advances in scanning and imaging techniques, including micro X-Ray Fluorescence (μXRF) scanning, Hyperspectral Imaging, Mass Spectrometry Imaging, and Micro-Computed Tomography (μCT) scanning, create new opportunities to explore geochemical and sedimentological records in unprecedented detail. These techniques complement traditional methods by enabling the integration of stratigraphic and sedimentological data with high-resolution paleoclimate reconstructions.
This session hosts all contributions that integrate conventional sedimentological, stratigraphic, and paleoclimatic methodologies, as well as contributions focusing on the development and use of cutting-edge imaging techniques to address methodological, sedimentological and paleoenvironmental research questions across timescales. We gathered and combined submissions highlighting innovative proxy applications, methodological advancements, and solutions to challenges in analyzing difficult archives. Our goal is to provide the platform to explore applications of conventional and imaging techniques in paleoclimate and geoarchaeology. By fostering discussions on integrating traditional and novel approaches, this session intends to spark interdisciplinary collaborations and inspire new research directions in understanding Earth and human history.

Solicited authors:
Pierre Francus
Convener: Igor Obreht | Co-conveners: Janina J. NettECSECS, Lars Wörmer, Melanie Kranz-Bartz, Petra ZahajskáECSECS, Christian Zeeden, Rik Tjallingii
SSP3.8 EDI

Sedimentary archives can be found across diverse environments worldwide, allowing investigation and disentanglement of past environmental processes over different setting. However, one key limitation in the investigation of such records is deciphering the complexity of how the different forcings acting in a natural system are manifested in the environment and consequently propagated into the studied archives. Interpretations derived from any sedimentary archive thus depend on a our understanding of the surrounding natural system itself and its web of feedbacks, the investigated sedimentary record, and the utilized proxies. Such interpretations often call for the integration of different disciplines, the development of new tools for sampling, novel laboratory methodologies and modelling. These studies need to integrate both modern and recent observations as well as reconciling these with numerical models to improve our predictions of coastal evolution in the future. Combining vast datasets from remote sensing, habitat mapping, geophysical surveys, and in situ monitoring, with advanced analytics and numerical models, provides a holistic view of coastal evolution.

For this session we welcome any contribution that integrates sedimentological, geochemical, biological, and geochronological methods, as well as modelling approaches, novel laboratory experiments and monitoring, for the interpretation of sedimentary systems, with a special focus on mechanism-oriented interpretation. Contributions that either focus on the development and calibration of novel proxies, analytical approaches (either destructive or non-destructive) and data analysis (statistics, machine learning, AI), or present interesting case studies, are welcome as well.

Co-organized by BG5/CL1.2/GI6/GM5
Convener: Shlomy VainerECSECS | Co-conveners: Peter Clift, Daniela J. M. MüllerECSECS, Ido Sirota, Federica Foglini, Ina Neugebauer, Yoav Ben DorECSECS
SSP4.1 EDI

Micropaleontological data, such as assemblage composition, morphology, and evolutionary patterns, provide unique insights into the dynamics and tipping points of past environments and climate through changes in the fossil record. Micropaleontology lies at the heart of biostratigraphy and provides a fundamental tool for reconstructing and stratigraphically constraining past changes in the Earth system. Our session aims to gather a broad spectrum of micropaleontologists to showcase recent advances in applying micropaleontological data in paleoenvironmental, paleoclimatological, and stratigraphic research in both marine and terrestrial settings.
We invite contributions from the field of micropaleontology that focus on the development and application of microfossils (including, but not limited to, coccolithophores, diatoms, dinoflagellates, foraminifera, ostracods, radiolarians, pollen) as proxies for paleoenvironmental and paleoclimatological reconstructions and tools for stratigraphic correlation. We particularly encourage the submission of multi-proxy approaches, merging micropaleontological information with geochemical and paleobiological information. The application of microfossils as stratigraphic markers and advancing multivariate statistical techniques with a focus on microfossil assemblages is encouraged.

Co-organized by BG5/CL1.2
Convener: Gerald Auer | Co-conveners: Deborah TangunanECSECS, Olga KoukousiouraECSECS, Arianna Valentina Del GaudioECSECS, Patrick Grunert
GM6.2

Currently drylands are home to >40% of the world’s population, and many prehistoric and historic cultures developed in these regions. Drylands are characterized by limited water resources and are highly sensitive towards both human activities and extreme events such as droughts and floods, which affects regional water balances and geomorphic processes. Due to currently intensified climatic and human pressure such processes strongly intensified during the last decades, affecting the living conditions of local populations including freshwater availability from groundwater resources and water quality. However, the functioning of these processes and their feedbacks are poorly understood. To build up reliable future scenarios to achieve sustainable development goals in the future these processes and feedbacks need to be addressed in an interdisciplinary manner on timescales ranging from the Quaternary until today, as well as in future climate scenarios.
This session pools contributions dealing with past to future hydrometeorological, environmental and geomorphological processes understanding in drylands across a broad geographical range since the Quaternary studied on varied spatial and temporal scales. Besides case studies on individual regions and review studies, cross-disciplinary, methodical and conceptual contributions are especially welcome in this session.

Co-organized by CL1.2/HS13/SSP1/SSS3
Convener: Hans von Suchodoletz | Co-conveners: Yves Tramblay, Janek WalkECSECS, Pedro AlencarECSECS, Joel RoskinECSECS
GM3.8

Coastal areas are among the most dynamic elements of the physical landscape, strongly influenced by both short-term (e.g., catastrophic meteo-marine events, human impacts) and long-term (e.g., tectonics, climate change, volcanic activity) forcing factors. Therefore, the study of coastal proxies can offer a series of benchmarks for estimating processes and associated timescales.
Among the most studied processes in coastal areas are relative sea-level changes. Any landscape feature whose environment of formation is linked to a former sea level can be used as a sea level index point (SLIP). SLIPs can be of different types: geomorphological (e.g., marine terraces, shoreline angles), biological (e.g., coral reef terraces), sedimentary (e.g., beach deposits, saltmarshes or beach ridges).
Although there is a comprehensive understanding of the relative sea-level changes during the Holocene, our knowledge of such dynamics during past interglacials remains limited. This session invites the international sea-level community to present studies broadly related to Quaternary interglacials. We welcome contributions on new field or remote sensing data, synthesis and databases specifically related to sea-level changes (including geochronological methods). We also welcome contributions exploring other coastal processes at the same timescale, focussing on wave conditions, extreme coastal events, and coastal modelling.
This session falls under the purview of PALSEA-Next, a working group of the International Union for Quaternary Sciences (INQUA) and Past Global Changes (PAGES) and from the WARMCOASTS project, funded by the European Research Council under the EU Horizon 2020 Research and Innovation Programme (grant agreement n. 802414).

Solicited authors:
Giovanni Scicchitano,Benjamin Horton,Adam Switzer
Co-organized by CL1.2, co-sponsored by PAGES
Convener: Ciro CerroneECSECS | Co-conveners: Giuseppe CorradoECSECS, Silas DeanECSECS, Ricardo Ramalho, Alessio Rovere

CL2 – Present Climate – Historical and Direct Observations

Sub-Programme Group Scientific Officers: Martin Wild, Kerstin Treydte

CL2.1 EDI

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.

Solicited speaker: Prof. Bill Collins, UC Berkeley

Solicited authors:
William Collins
Co-organized by AS3
Convener: Martin Wild | Co-conveners: Jörg Trentmann, Maria Z. HakubaECSECS, Paul Stackhouse
CL2.2 EDI

ENSO and the Tropical Pacific as well as their interactions with other tropical basins are the dominant source of interannual climate variability in the tropics and across the globe. Correctly modelling and understanding the dynamics, predictability, and impacts of ENSO, as well as anticipating their future changes are thus of vital importance for society. This session invites contributions regarding all aspects of ENSO, Tropical Pacific 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, climate change over the last few decades 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.

Convener: Yann PlantonECSECS | Co-conveners: Anna-Lena Deppenmeier, Dietmar Dommenget, Sarah Ineson, Fred Kucharski
CL2.3 EDI

Urban areas play a fundamental role in local- to large-scale planetary processes via modification of heat, moisture, and chemical budgets. With urbanisation continuing globally, it is essential to recognize the consequences of converting natural landscapes into a built environment. Given the capabilities of cities to serve as first responders to global change, considerable efforts are currently dedicated across cities to monitoring and understanding urban atmospheric dynamics. Various adaptation and mitigation strategies aimed to offset the impacts of rapidly expanding urban environments and influences of large-scale greenhouse gas emissions are developed, implemented, and evaluated. Tools and services tailored to cities that support climate action are rapidly evolving.

This session solicits submissions from the observational, modelling, and science-based tool development communities. Submissions are welcome that cover urban atmospheric and landscape dynamics, urban-climate conditions under global to regional climate change including uncertainty propagation, processes and impacts due to urban-induced climate change, the efficacy of various strategies to reduce such impacts, and human-biometeorological investigations in urban settings. We also welcome techniques highlighting how cities use novel science data products and tools, including those from humanities and social sciences, that facilitate planning and policies on urban adaptation to and mitigation of the effects of climate change. Emerging topics such as citizen science, crowdsourcing, machine learning, and urban-climate informatics are highly encouraged.

Solicited authors:
Dev Niyogi
Convener: Rafiq Hamdi | Co-conveners: Daniel Fenner, Gaby Langendijk, Ariane Middel