The climate of the past two millennia (2k) is vital for developing our understanding of the climate system, as it extends the historical climate record and provides important context for recent and future changes. We invite contributions that build on the four key objectives of Phase 4 of the PAGES 2k Network:

The climate is highly variable over huge ranges of scale in both space and in time. Classical frameworks for handling such variability are “scalebound”, they ignore the continuum variability and isolate processes acting over narrow ranges of scale. Yet it was recently discovered that the ignored background had been underestimated by an astronomical factor: instrumental and paleodata shows that it accounts for the great majority of the variability.
New approaches based on scaling processes acting over wide ranges of scale must be developped. Using scaling, paleodata objectively shows that the climate is composed of three regimes: climate, macroclimate and megaclimate with transitions at ≈ 100kyrs and ≈1 Myr respectively. Narrow range processes can only be understood in the context of their corresponding scaling regime.

 

This session has grown out of the PAGES Climate Variability Across Scales (CVAS) working group that was established precisely in order to understand, model and analyse scaling climate processes. While CVAS focused on the Quaternary and Pleistocene epochs, this session extends the CVAS purview to include the longer duration mega-climate regime bio-geological processes i.e. with scales ≈ 1 Myr and longer (straddling the Phanerozoic and early Earth epochs).

 

This session welcomes papers dealing with:
a) Methods for characterizing the spatial and temporal variability of the climate and its proxies This includes the effect of spatial and temporal resolutions of the data. Spectral, fluctuation, wavelet, fractal, multifractal and other analysis techniques are welcomed.
b) Methods for characterizing paleochronologies and correcting for their strongly nonuniform nature.
Most paleo series are derived from cores formed by highly variable (often scaling) sedimentation and erosion processes with the result that the paleodata are sampled with highly variable resolutions (measurement densities).
c) Methods for relating paleo signals to standard climate variables:
Methods that make climate proxies that are closer to the real climate.
d) Methods for characterizing the (scale by scale) correlations, interactions between paleo processes:
This includes cross spectral, cross fluctuation and recurrence plot analysis.
e) New ways of modelling paleoclimates with their variability.
These include stochastic, fractal and multifractal models, and models based on fractional differential equations.

Human Traces is a PAGES working group which aims to synthesize records of human traces in natural archives, to improve our understanding of the timing, nature and magnitude of human impacts on the environment. The objective of this session is to gather researchers working on any aspect of human traces in the geologic record, from signs of human presence to clear evidences of human activities.

 

Data presented in this session will be considered for inclusion in the Human Traces database, a new resource that the working group is developing which aims to assemble information that will enable the establishment of temporal trends of human activity linked to environmental change across various spatial and temporal scales.

 

Researchers working on Human Traces records from Asia are kindly invited to participate in our workshop which will follow the Open Science Meeting, and will aim at a regional/continental synthesis.

In this session, we aim to: 1) discuss the major issues relating to the effective conservation of biological diversity in various biomes, and how a trans-disciplinary approach could help in dealing with them, 2) cross-compare the management solutions for maintaining the stability and sustainable development of the ecosystems under different national and continental schemes, and 3) identify the best conservation approaches following transdisciplinary approach, a merge between paleo- and neo-ecology and socio/cultural disciplines, to resolve the environmental issues from the respective regions.

We welcome contributions from the paleo-environmental community as well as local stakeholders from different regions interested in showcasing and co-developing a transdisciplinary approach to ecosystem conservation. The contribution and knowledge exchange from various biome regions including forest ecosystems, grasslands, savannas/forest-grassland transitions.

This session “Transdisciplinary approach to resolve environmental issues” proposed by DiverseK Working Group (WG) will serve as a crucial event for fostering interdisciplinary scientific exchange and international collaboration to identify natural and anthropogenic (biocultural heritage) components of social-ecological systems and promote paleodata-driven practices that help maximize biodiversity and resilience in ecosystems. This session aligns perfectly with the overarching objectives of the 7th PAGES OSM meeting, seeking to explore the Earth ecosystems changes from the Past towards the Future.

Paleo studies present a unique opportunity to quantify the magnitude, rates, and drivers of sea-level and ice-sheet variability over hundreds to millions of years. Recent advances in the field have led to the establishment of international standards for the collection, reporting, and open-access sharing of past sea-level data in the observational approach, as well as improved understanding of, and computational capabilities in modeling physical processes of paleo sea-level change and its drivers. These improvements will allow us to better inform predictions of future ice sheet, sea level and coastline evolutions.

 

This session is organized by the PALeo constraints on SEA level rise (PALSEA-Next) Working Group, with an aim to bridge researchers from interdisciplinary backgrounds, spanning from proxy-reconstruction to geophysical process modeling. We welcome contributions that integrate state-of-the-art modeling with geological and archaeological records to provide crucial context for modern observations and future projections. In particular, topics to be explored include, but are not limited to: i) providing the evidence and mechanism of drivers of ice sheet and sea-level changes, ii) improving understanding of global or regional-scale sea-level changes due to ice volume change and related physical processes, and iii) exploring of the role of sea-level and coastal landscape modification in the evolution of human societies over multidecadal, centennial and millennial timescales.

The scope and severity of low oxygen zones in marine environments are escalating in tandem with ongoing climate change, amplifying the urgency to understand historical oxygen levels to better contextualize current and future scenarios. Additionally, ocean acidification and shifts in pH levels are emerging as critical stressors, further complicating marine ecosystems' responses to global changes. The field of reconstructing past marine oxygenation and acidification remains relatively nascent. However, its growth presents unique opportunities for expansive interdisciplinary collaboration, bridging modern and paleo-oceanography, geochemistry, sedimentology, and modeling across various temporal and spatial scales. This session encourages contributions that enhance our understanding of historical marine oxygenation and acidification. We particularly welcome studies that explore how marine oxygen and pH levels respond to global changes or extreme climate conditions and the principal drivers of these changes from seasonal to multimillion-year timescales. We invite both empirical data and model-based reconstructions, alongside innovative developments and applications of proxies tailored to marine oxygenation and acidification.

The evolution in the mode and tempo of glacial cycles over the interval 1.5 to 0.8 million years ago (Ma) remains one of the enduring mysteries of Quaternary paleoclimate. In the Early Pleistocene, glacial cycles appear symmetric with smaller ice volumes and a period of ~41 kyr. From about 1.5 to 1.25 Ma, the oxygen isotopic record of benthic foraminifera is marked by an exceptionally pure 41-kyr cycle, with glacial-interglacial cycles tightly phase-locked with the obliquity cycle. Closer inspection has shown that these cycles are not always symmetric, with more rapid deglaciations than glacial inceptions, implying the presence of some non-linearity, that becomes more noticeable with the onset of the so-called Early–Middle Pleistocene Transition (EMPT) to longer (~100 kyr), stronger and more 'saw-tooth' shaped glacial cycles. Hypotheses on the causes of the EMPT involve land surface/cryosphere, ocean-atmosphere or carbon cycle changes. In this session, we invite contributions from the data and modelling communities that provide insights into the nature of millennial- and orbital-scale climate variability and advance understanding of the dynamics of this transition.

Paleoecological data holds immense potential for guiding ecosystem restoration initiatives and supporting Sustainable Development Goals (SDGs) in the Anthropocene. However, translating these insights into actionable strategies remains challenging despite established framework, such as historical reference /baseline condition. For instance, setting realistic restoration targets and effectively combing paleo-data with modern monitoring or remote sensing data are significant hurdles. Furthermore, as we confront future conditions without past analogues, restoring ecosystems to previous states may not be feasible or desirable considering the changes in land-use and management.

This session seeks to facilitate discussions on the integration of paleoecological insights into restoration policy and broader environmental goals such as the SDGs and the UN Decade on Ecosystem Restoration (2021-2030). We welcome theoretical and empirical case studies from diverse geographical contexts, demonstrating how paleoecological data, either independently or in conjunction with other disciplines, informs restoration policy. By showcasing interdisciplinary collaborations and innovative methodologies, this session aims to facilitate knowledge exchange and catalyze actionable strategies for sustainable ecosystem restoration. Through diverse perspectives and dialogue at the science-policy interface, we seek to overcome existing obstacles and harness the full potential of paleoecological data in advancing environmental conservation and restoration efforts.

Paleo-archives such as speleothems are proving to be very valuable for reconstructing past climates and environments. Increasing access to chronological tools such as radiometric dating, age-depth models and confocal imaging techniques has significantly improved age control and temporal resolutions of these reconstructions. Remarkable developments in the interpretations of existing and novel proxies are being enabled through analogue laboratory experiments, monitoring studies, archive databases, process and proxy system models, as well as multi-proxy and multi-archive approaches. In this session, we welcome abstracts using these approaches to fill climatic and environmental reconstruction gaps, as well as studies working on improving our interpretations of proxies and enhancing our understanding of climatic events and processes.

Past volcanic eruptions have seriously impacted both the global climate system and human societies. They have been linked to global cooling, monsoon failures, famine, conflict, and social and political change. Until now, most studies have addressed eruptions as single events, albeit with temporally extended effects. However, new research is identifying more major double eruptions (two closely spaced eruptions) in the historical period than had previously been assumed, bringing with them the potential for unique climatological and social consequences (Toohey et al., 2016; Brönnimann et al. 2019). Even the definition of a double eruption is open to debate, since it is still unknown over what interval the effects of successive volcanic eruptions can still interact. In turn, their impacts on both climate and society may vary significantly from single eruptions, but if so, and how, is still the subject of ongoing research.

This session will begin to answer some of the questions surrounding double eruptions, presenting the most recent research on:

• Identifying double eruptions – using historical documents, climate records, geological and ice core archives.
• Whether double eruptions offer better analogues for geoengineering by stratospheric sulfur injections?
• How double-eruption climate impacts differ from those of single eruptions.
• The agricultural and societal impacts of selected double eruptions

Outreach is a critical part of the work as scientists. Bringing scientific results to the public help them to learn more about the natural world.

Scientists are continuously developing new ways of combining the different scientific approaches to the study of the past and its communication to students, educators and stakeholders. This session will showcase the best examples of outreach products and events in paleosciences, as well as ongoing projects in the field of paleosciences.

The discussions stimulated by these presentations will aim to bring out new ideas and directions in the field and establish a network of skills and resources to push towards a future for the Past Global Changes Horizons magazine.

The challenge of outreach, whether it be speaking, writing, illustrating or event coordination, is real for paleosciences. A challenge is posed by the complex nature of the Earth system, including in particular the time perspective with multiple scales, the integration of data and model approaches, spatial issues, and ongoing global change.

The paleosciences community must commit to ensuring that the latest research findings are disseminated as widely and quickly as possible to all citizens, especially the youngest generation, who will soon be responsible for our future.

The 2023 IPCC report highlighted the complex climate feedback processes operating in the Arctic (collectively known as “Arctic Amplification”). Documenting the environmental changes in the Arctic and sub-Arctic is a fundamental step towards understanding Quaternary global climate variability. The interaction between the Arctic and sub-Arctic profoundly impacts climate in the Northern Hemisphere and globally. The Arctic perturbs the delicate salinity balance in the polar and subpolar North Atlantic by exporting freshwater, which modulates global ocean circulation. On the other hand, warm water inflow from the North Atlantic and North Pacific via the Fram Strait/Barents Sea and the Bering Strait are critical drivers for Arctic environment change. Heat and moisture transport from lower latitudes by atmospheric circulation determines the build-up and retreat of Arctic ice sheets and sea ice, as well as further feedback to subpolar oceans and continents. The extent to which these processes function in the Quaternary at different time scales cannot be fully assessed due to the lack of high-resolution paleoceanographic records from the critical locations of the polar and subpolar regions. The development of larger and longer- lasting Northern Hemisphere ice sheets during the mid-Pleistocene Transition (MPT) coincided with global cooling. Moreover, there is generally a lack of comparable records from the Arctic and the sub-Arctic to evaluate the synchronization of climate evolution.

We invite contributions dealing with the following aspects of the Arctic and sub-Arctic climate: i) the timing and magnitude of both short and longer time scales, i.e., Terminations and deglaciations and glacial-interglacial cycles; ii) the evolution and transition of the polar and subpolar climate during the Quaternary; and iii) the interactions between the subpolar and subtropical climate systems in paleo time scale. We also strongly encourage contributions from modeling studies that combine empirical and theoretical perspectives.

Natural past climate changes have had a profound impact on ecosystems across the globe, driving significant shifts in species distributions and altering biodiversity. The ongoing climate change is expected to have a profound impact on the diversity of modern plants, with many biomes projected to experience a species extinction rate of between 15% and 20% by 2050. However, recent trends in the extinction rate remain unclear, and it is uncertain which regions will be most affected in the near future, given the significant regional biotic and abiotic differences.

Palaeoecological records provide valuable insights into the past occurrence and distribution of plant species, as well as their contemporaneous climate, allowing for a comprehensive analysis of the impact of natural climate-induced changes on ecosystems over time and across different spatial scales.

The objective of this session is to showcase how past environmental data can be used to assess past biodiversity, identify biomes or ecosystems at risk, and develop new strategies and approaches for managers. We welcome a broad range of multidisciplinary approaches that integrate past environmental reconstructions, ancient DNA, vegetation/species modeling, and other approaches that can help improve our understanding of the local or regional threats posed by ongoing climate changes to ecosystems and species, and contribute to their long-term conservation.

Atmospheric particles derived from natural and anthropogenic sources have a range of effects on the Earth’s climate, ecosystems and humans. Mineral dust as well as volcanic and some anthropogenic aerosols play an important role in global climate and have significant implications on the Earth’s radiative balance, cloud properties, atmospheric chemistry and fertilization of terrestrial ecosystems. Additionally, industrialization and urbanization has resulted in an increase of atmospheric pollutants such as metals and metalloids but also new types of pollutants including nano- and micro-plastics, organics aerosols or other technogenic particles referred as emerging pollutants.

Ice cores, ombrotrophic peatlands (peat bogs) and small lakes are ideal archives to study past changes in atmospheric particles. While these archives have been instrumental in improving our understanding of understanding of environmental and climatic changes, certain gaps remain. For example, a large part of those studies focused on total concentrations of elements (ex. REE, Ti, Zr for dust and Pb, Hg, PAH for anthropogenic impacts) and isotopes (Sr, Nd, Pb) for source tracing and tracking changes in air masses. Paleo-particle records remains to be fully developed in reconstructing air masses trajectories and past wind regime as particle emission responds non-linearly to climate and source regions can respond differently to environmental changes. Additionally, few studies have considered the deposition process (wet vs. dry deposition) when reconstructing atmospheric particle records. Finally, records of “emerging” atmospheric pollutants such as micro-plastics remains limited and robust methods are still being developed for some types of archives (ex. peat bogs).

This session covers topics related to the atmospheric paleo-particles and their environmental and climatic impacts. Key themes include (i) proxy-based studies on “natural” atmospheric particles (mineral dust, volcanic particles) as well as atmospheric pollutants either traditional (ex. harmful trace elements, polycyclic aromatic hydrocarbon) or emerging (microplastics, black carbon, and brown organic carbon); (ii) studies focusing on the depositional processes and speciation of atmospheric particles (ex: wet vs. dry dust deposition), (iii) modelling studies; (iv) the use of novel approaches or technical developments to extract atmospheric particles from paleo-records.

High-latitude and high elevation ecosystems are particularly vulnerable to environmental change. In recent decades, the polar regions and high mountains including Tibet have experienced more pronounced climate warming than other parts of the World. Rising air temperatures and changing snow regimes are expected to cause permafrost degradation and shifts in vegetation patterns in tundra and forest biomes. The aim of this session is to present a wide range of research methods and results related to climate and environmental changes in permafrost regions during the Holocene.

These include but are not limited to (a) local, regional and global-scale reconstructions of vegetation, fire regime and environment changes using palaeoecological and geochemical proxies, (b) reconstructions of climate changes and permafrost dynamics during the Holocene and in the recent past, (c) the development and application of innovative methods and archives for investigation of natural processes in permafrost regions, (d) interaction of climate and environment changes with the greenhouse gases emission in the permafrost regions. We invite experts from different scientific fields to present new results of experimental and theoretical studies focused on permafrost areas, based on detailed palaeobiological information (pollen, macrofossils, diatoms, testate amoebae, etc.); tree-ring data; geomorphological, paleolimnological and paleohydrological materials; stable isotope records; radionuclides tracing and evidence of human activities. Particular attention will be given to studies focusing on remote and poorly investigated areas in Tibet, Siberia and the Russian Arctic.

We encourage submissions of novel ideas and hypotheses, particularly from early career researchers, and hope that the session can create an environment where such ideas can be freely discussed.

New technologies facilitate the development of novel proxies to advance paleoclimate studies to improve our understanding of diverse marine and terrestrial environments. These proxies operate by capturing the contemporary relationship between sediments/fossils and ambient waters, thereby serving as indicators of past environmental conditions. Spanning a wide array of materials, from (micro)fossils and deep-sea sediments to inland water bodies, loess deposits, and sediment-embedded dust particles, they offer insights into past rainfall and temperature (e.g., sea surface temperatures) reconstructions, seawater densities, oxygen levels, temperature-salinity characteristics, primary productivity, ocean acidity, land-ocean-atmosphere interactions, erosion patterns, and variations in ice-sheet extent, among other parameters. Aiming to share updates on novel climate proxies in Earth Sciences disciplines, this session promotes interdisciplinarity and welcomes all studies that focus on proxy development to deepen our understanding of Earth’s past climates across various geological time scales.

Drylands, spanning approximately 41% of the Earth's land surface, are home to over two billion people. Over recent decades, the combined effects of climate warming and intensified human activities have accelerated environmental degradation and desertification in these regions, posing significant threats to the economies and sustainable development of nations. The release of dust from these expansive dryland areas plays a crucial role in Earth's climate system, with dust storms emerging as a severe environmental challenge faced by numerous countries worldwide. The eolian processes and landscape dynamics in drylands have the potential not only to impact regional environments but also to profoundly affect atmospheric and soil conditions in downwind regions through the long-range transport of fine particles. This session aims to explore the latest research advancements within this intricate yet interconnected field and to gain a comprehensive understanding of how dryland landscapes respond to past and current climate change with new techniques and emerging evidence.

This session will explore the archaeological impacts of abrupt climate change and ecological tipping points. In 2021, MPI Hamburg meteorologist Victor Brovkin along with colleagues, published the seminal review paper in Nature Geoscience titled “Past abrupt changes, tipping points, and cascading impacts in the Earth system.” They used well-documented abrupt changes from the past 30,000 years to illustrate how physical climate systems, ecosystems, and societies can create cascading effects across these interconnected components of the Earth system. Building on this approach, we propose investigating rapid cultural change events of the late Pleistocene and Holocene. Sedentary societies with agriculture and livestock, as well as nomadic pastoralist societies, appear significantly more vulnerable to environmental influences compared to non-sedentary hunter-gatherer societies. The proposed session aims to identify rapid cultural change events and tipping points in human evolution that extend beyond those discussed in the Brovkin et al. paper.

We believe there is significant potential for further archaeological investigation to fully uncover the impact of these changes on human societies. We welcome contributions that explore climate-induced societal changes, which may have either negative (societal collapse, wars, and violence, societal vulnerability) or positive impacts (population growth, improved crop yields) on societies. Additionally, contributions that highlight rapid cultural change events due to factors other than climate change, that makes societies vulnerable to external effects, such as pandemics or population density, are also encouraged. Contributors should take a critical view of the chronological resolution of their time series and strive to capture environmental impacts with high precision.

We invite papers for this session that might explore, but need not be limited to these key areas:
-Human Responses to Dynamics in the Cryosphere, Atmosphere and Hydrosphere: Examining how the rapid disintegration of ice sheets and subsequent sea-level changes as well as abrupt climatic shifts might have influenced (early) human settlements and migrations, reshaping human habitats and resource distributions in profound ways.
-Agricultural Adaptations to Vegetation and Forest Shifts: Analyzing the impacts of sudden shifts in vegetation, such as the dieback of major forests, on the development and sustainability of early agricultural practices, and the impacts of those on the vegetation and forest cover. This might include how abrupt ecological changes forced agricultural societies to adapt or find new ways to sustain their communities.
-Impacts on Hunter-Gatherer Societies: Investigating how abrupt climate and ecological changes affected hunter-gatherer societies, focusing on changes in migration patterns, resource availability, and technological innovations. This theme might delve into how these societies adapted to or were disrupted by sudden changes in their environments.
-Archaeological Indicators of Climate and Social Tipping Points: Presenting archaeological findings as indicators of past ecological, climate, and social tipping points. This may highlight how archaeological data, when aligned with paleoclimatic evidence, enhances our understanding of the triggers and impacts of social tipping points that influenced human societies.
-Synthesizing Paleoclimatic, Archaeological, and Social Data: Emphasizing the importance of integrating paleoclimatic evidence with archaeological and sociological records to build comprehensive narratives about how human societies navigated abrupt environmental and social changes. This synthesis may aim to provide deeper insights into human resilience and adaptability.
-Independent Dynamics of Social Tipping Points: Investigating how social tipping points can arise independently from ecological or climate triggers, creating feedback loops that can significantly influence the trajectory of societal development. This area will explore how these social dynamics, both positive and negative, interact with environmental factors to shape the course of human history.

 

This session is designated to foster a multidisciplinary dialogue among archaeologists, climatologists, historians, and social scientists, to explore the potential of archaeological research in understanding how past human societies were shaped by and responded to abrupt changes in their environment. By combining detailed archaeological evidence with paleoclimatic and social data, we aim to enrich our understanding of the complex interactions between human cultures and dynamic Earth systems, revealing deeper insights into past human resilience and strategies for navigating future climate challenges.

Written records provide unique high-resolution weather and climate information and their societal context, particularly for periods before modern instrumental measurements. Methods of historical climatology have been employed for reconstruction of daily, monthly, and seasonal temperature and precipitation, wind direction, and extreme events for past centuries throughout diaerent world regions. This session invites new research utilizing written records for climate and weather reconstruction, as well as their historical context and consequences. Topics may include:
- New historical sources, databases, and data rescue
- New methods for reconstruction utilizing written sources
- New approaches for integrating written and physical evidence of past climate and weather
- Studies of historical climate and weather impacts or adaptation utilizing written records
- New methods or case studies for analyzing climate-society links including migration and conflict
We encourage submissions that consider the conference general theme ‘Earth System Changes from the Past towards the Future’ and address possible insights from historical climate change and impacts for climatic changes change in the 21st century.

Our proposed session aims to showcase current paleoclimate research on major lakes and river systems, specifically those that incorporate practical implications for communities that rely on these water sources. From the Mississippi to the Amazon, from the African Great Lakes to the Tibetan Plateau, we invite contributions that reveal the mechanisms of past hydroclimate regimes and utilize a variety of scientific approaches to studying these vital systems.

As we prepare for an increase in the frequency and intensity of extreme climate and weather events on Earth, it is critical to constrain long-term trends and future projections of climate variability. Our session invites contributions that focus on human activities and water systems. In addition, we encourage research on their diverse impacts on cultural heritage, agriculture, industry, and beyond.

We welcome submissions that address, but are not limited to, the following themes:

Moreover, we encourage submissions that advocate for ethical research protocols and foster meaningful partnerships with indigenous and local communities, aiming to empower inclusive and collaborative approaches. In doing so, we hope to unite an interdisciplinary group of researchers focused on equipping communities for the uncertainties of future climate change.

Millennial-scale changes in the strength of the Atlantic Meridional Overturning Circulation, a societal relevant tipping element of the climate system, are believed to have a profound effect in tropical precipitation. Despite key findings about millennial-scale changes in tropical precipitation achieved during the last few decades, many central questions remain unanswered. For instance, the exact spatial coverage, internal structure and timing of millennial-scale changes in tropical precipitation are still uncertain. These topics assumed a particularly large relevance because the Atlantic Meridional Overturning Circulation may show a substantial weakening until the end of this century due to anthropogenic-driven climate change. In this session, we welcome studies investigating millennial-scale changes in tropical precipitation based on both continental and marine archives of all continents and oceans, as well as model approaches. By scrutinizing past hydroclimate changes we expect to shed light on potential future scenarios.

This session aims to address the urgent need for a better understanding of potential threshold shifts and hysteresis within the Earth’s climate and ecosystems, spanning global, regional, and local scales across time. This knowledge is crucial for developing strategies to adapt and mitigate the impacts on society and environment. By assessing thresholds, tipping points, and abrupt climate changes utilizing comprehensive paleo proxy reconstructions and climate model simulations, this session seeks to convene experts for collaborative efforts aimed at exploring tipping elements and their critical thresholds within a paleoclimatic context. The leverage of both proxy records and modeling approaches to study tipping points across broader temporal and finer spatial scales makes us capable of identifying potential gaps in current tipping point research. In this session, we invite abstracts from: 1. The ongoing tipping point-related projects such as TIPMIP, WhatIfMIP, TIPESM, CLIMTIP, and others focusing on large-scale changes like the Atlantic Meridional Overturning Circulation, ice sheets, permafrost, and tropical and boreal forests, utilizing either models or proxies or both; 2. Empirical, modeling, and theoretical studies of tipping point within our climate and ecosystems at smaller scales such as coral reefs, lakes, cryosphere (sea ice, glaciers and mountain ice caps), biodiversity, etc.

Many regions around the world are experiencing unprecedented environmental changes that are becoming increasingly challenging for humans and ecosystems to adapt. Model projections suggest an even more challenging future yet continue to exhibit large levels of uncertainty despite many generations of model development, particularly for future rainfall change. The paleoclimate record offers an opportunity to produce more accurate projections through exploring whether models can simulate responses and consequences outside those experienced over the instrumental period. To best leverage the paleo record, new approaches are needed to provide process-based insights into how models simulate atmospheric and oceanic variability and change driving extreme drought and rainfall, as well as how to improve them. We invite contributions that offer novel, quantitative approaches to the evaluation of models using paleodata, with a focus on advancing climate prediction and our understanding of whether models can simulate forced and unforced variability. Studies using high resolution models, reconstructing past climate extremes, and tipping points are encouraged.

Climate variability in the tropical oceans has strong impacts worldwide, but uncertainty remains in its response to changes in the mean climate and external forcing. Past efforts have mainly focused on the El Niño-Southern Oscillation (ENSO) and its teleconnections, although bodies of literature are emerging about climate variability in the Atlantic and Indian Oceans as well. Recent studies have revealed the interdependence of the tropics, for example showing the Atlantic Multidecadal Variability (AMV) can modulate ENSO variability and exploring the shifting relationship between the Indian Ocean Dipole (IOD) and ENSO. These findings have profound implications for predictability, suggesting that future projections may not uniformly reflect inter-basin changes. Thus, there is a pressing need to delve deeper into understanding how climate variability within each basin is influenced by changes in mean state and how inter-basin connections are altered.

Past climates provide a natural laboratory to explore how changes in forcings such as CO2, ice sheets, and insolation have shaped mean state changes and subsequent climate variability, impacting inter-basin exchanges. Recent endeavors in paleoclimatology, including proxy data synthesis, model intercomparison studies, and model-data comparisons, have provided invaluable insights into past tropical climate variability. These studies demonstrated that it is now possible to go one step further in understanding the underlying mechanisms, partly due to increased Earth System Model (ESM) resolution and complexity. This is also explained by the better spatial coverage, resolution, age control and complementarity climate information between the different high resolution proxy records (e.g., corals, shells, tree rings, speleothems, varved sediments) and climate reconstructions from sediment cores or pollen records. By leveraging paleoclimate data and modeling approaches, we can enhance our capacity to anticipate and mitigate future changes in tropical climate mean state and variability despite inherent differences between past and future conditions.

One goal for this session is to find how interannual variability in those tropical basins are affected by mean state changes. This session seeks contributions from paleo-data and modeling studies looking at one or more tropical ocean basins, particularly those that emphasizing research bridging the gap between models and data.

Ash expelled during explosive volcanic eruptions (tephra) can be employed to provide robust and precise chronological synchronisation (tephrochronology) that is key in palaeoenvironmental studies. Identification of these tephra layers and correlation of high-resolution paleoclimate proxy records provides an opportunity to understand leads and lags in the climate system across abrupt transitions. In addition, the release of tephra and gas from volcanoes during medium to large eruptions impacts the environments on both regional and global scales and can significantly alter the climate for numerous years. These impacts can be predicted and assessed by quantifying the amount of volatiles (particularly sulphur) released during the eruptions and interrogating climate proxy records, respectively. Ashfall also disrupts air travel, damages infrastructure, and threatens public health. With current climate change trends possibly exacerbating the frequency and intensity of volcanic activity, understanding the interactions between tephra, volcanism, and the environment is increasingly critical for mitigating risks and adapting to these hazards.

By studying layers of tephra deposited in sedimentary archives or ice cores, researchers can pinpoint precise dates of past volcanic events. These tephra layers provide invaluable insights into past volcanic eruptive histories, including sizes and the dispersals of events. Such data is key to forecasting future eruption scenarios and establishing the hazards that volcanoes pose to society. This session invites participants to share research on: volcanism and hazards; tephrochronology and its applications in Quaternary Sciences and Volcanology; and methodological and analytical advancements, including the use of machine learning and AI.

Eruption histories and the ability to reliably use tephrochronology is well established in some regions, such as NW Europe, the Mediterranean and Japan, whereas there are many areas where this potential is only starting to be realised. We welcome contributions from different regions where the analyses of tephra can improve our wider understanding of past eruptive activity, and paleoenvironmental or cultural change through using tephra as a dating and correlation tool.

Fire is a deeply integrated Earth System component. From the land to the ocean, from ecology to people, and from the past to the future: fire is a genuinely transdisciplinary research topic. However, integrated research across disciplines, institutions, and fire practitioners into its myriad connections throughout the Earth System and interdependencies with society is not enough established. This creates barriers to a holistic understanding of how the rapid changes we are seeing in the fire regimes will impact the health of our planet and its inhabitants.

Diverse expertise from across the geosciences, environmental and social sciences is needed to fully characterise and identify the main challenges facing fire science. This session is to design and develop a proactive approach to advancing transdisciplinary past fire science, including data and modelling, providing past reconstructions as a framework for knowledge transfer to all fire sciences. Recognizing the multidimensional nature of fire, the first goal of this session is to initiated collaborations across continents, disciplines and expertise.

Building upon the momentum of a Future Earth COP27 side event on fire, the FLARE working group was launched at a workshop held online and in-person at the Bermuda Institute of Ocean Science (BIOS) in September 2023, providing a platform for discussing the latest scientific knowledge on fire. The workshop facilitated the promotion and integration of cutting-edge satellite data, on-site fieldwork, laboratory experiments, social science, mathematics, and modelling with the broad range of expertise essential for addressing diverse research questions related to fire. Striking a balance between contemporary research and a robust paleofire perspective, the workshop offered insights into how fire regimes have shaped and continue to shape the Earth System, particularly in response to climate change and human activities.

This session aims to highlight the current state-of-the-science from land, atmosphere, ocean and society about past fire time series and models. The session goal is the understanding of “future impacts of fires on the Earth System”. We encourage submissions that use models across different spatial scales and/or measurements from field campaigns and laboratory experiments. Particular interests are, but not limited to, the following three main challenges identified by the global fire community at previous workshop discussions:

The thermohaline circulation redistributes heat and moisture across the globe, a role often attributed to surface currents and deep waters. Nonetheless, intermediate depth water masses (such as the Arctic and Antarctic Intermediate Waters, the Mediterranean Outflow Water or the North Pacific Intermediate Water) have an important yet underexplored share in the global circulation. During past glacial periods, it was suggested that the deep waters shoaled possibly into the intermediate waters, while the abyssal water masses entered a somewhat dormant state. Additionally, intermediate depth waters have a considerable impact on the global redistribution of oxygen, nutrients, and carbon, on decadal time scales. Regionally, such water masses can affect primary production and carbon sequestration. Aiming to improve our understanding of their histories, this session welcomes contributions focusing on the evolution of intermediate waters throughout all geological time scales registered by all paleoceanographic and paleoclimatic archives and proxies, as well as by modeling experiments.

Understanding the processes that govern the long-term evolution of the southeast Asian monsoon came to sharp focus with the completion of a few recent drilling projects on the northern tropical Indian Ocean, i.e., Bay of Bengal, Arabian Sea, and South China Sea, by the International Ocean Discovery Program (IODP). As a result, new insight began to unravel for shorter and longer time -scales by analyzing fresh marine sediments. Further, since discovering the Dansgaard-Oeschger climate events in Greenland ice cores and their equivalent events in the North Atlantic marine sediments, the low-latitude paleoclimate records document similar changes in tropical climates. Such millennial-scale climatic variabilities are manifested by substantial precipitation and temperature perturbation recorded in marine and terrestrial paleo-archives such as speleothems, loess, and sediments. While the paleo-proxy records from the northern tropics and subtropics mainly show concordant climate changes with those of the North Atlantic during the last glacial-interglacial cycle, asynchronous and even anti-correlated phenomena are exhibited in the southern hemisphere. For example, the Indian and East Asian monsoon systems seem tuned to the North Atlantic climate, whereas the South American monsoon appears to operate differently. Moreover, paleo-proxy records from the equatorial Pacific are characterized by a complex pattern of millennial-scale change that borrows elements from the northern and southern hemisphere end-members. There is a growing consensus that these abrupt millennial-scale climate events involved a reorganization of the Atlantic Meridional Overturning Circulation (AMOC), driven by the meridional heat and moisture transport. The perturbation of the AMOC has been dynamically linked to Intertropical Convergence Zone (ITCZ) variability, which is tied to coupled dynamics in the tropical Pacific. However, the physical mechanisms that link the climate system elements are not well understood.

We invite contributions dealing with the following aspects of the Southeast Asian monsoon systems: i) the timing and magnitude of both short and longer time scales, namely the Holocene and glacial cycles using paleo-archives (i.e., caves, loess, lake, and deep-sea sediments, etc.); ii) evolution of the Indo-Asian monsoon during the Quaternary; iii) the relationship between the tropical and the high-latitude climate systems in paleo time scale; and iv) sedimentary record related to monsoon evolution during the Quaternary (i.e., sediment source-sink, plaeo-CO2 reconstruction, ocean heat content and associated surface stratification, etc.). We also strongly encourage contributions from regional synthesis and modeling studies that combine empirical and theoretical perspectives.

Anticipating trajectories of the Earth System under projected anthropogenic activities relies substantially on understanding the past climate-human-environment nexus. Despite advances in proxies and a significant increase in paleoclimate and human activity records, gaps in paleoenvironmental data from remote regions hinder our understanding of future developments. These gaps stem among others from logistical challenges, historically marginalized scientific collaborations, or other research priorities, leading to unevenly distributed records across the Globe.

Most proxy reconstructions are clustered primarily in the mid latitudes of the Northern Hemisphere, while extensive regions in the Southern Hemisphere, as well as tropical and high-latitude areas remain underrepresented. This spatial bias prevents us from fully understanding the variability and complexity of human-climate interactions across different regions and environments, potentially skewing our global climate understanding.

Under this rationale, this session aims to highlight Holocene records of past environmental, climate, and human interactions from remote areas, particularly from regions historically marginalized from scientific collaborations, such as the Global South, remote islands, high latitudes and other underrepresented regions.

We encourage contributions that apply interdisciplinary and inclusive approaches to determine the drivers, magnitude, and rates of change of different components of the past climate-human-environment nexus. We aim to create a stimulating environment for exchange among researchers in paleoclimatology, paleolimnology, archaeology, biogeochemistry, etc.

We particularly encourage submissions presenting new environmental and climate reconstructions from various archives from remote areas, employing novel proxies to detect climate, human traces, and environmental changes, along with emerging measurement techniques, and archaeological data. This session aims to further stimulate collaborative avenues by bringing together scientists working on different topics in paleo sciences and archeology.

The Arctic cryosphere is changing rapidly due to increased runoff from land, changing sea-ice regime and the degradation of the circumpolar permafrost zone, having a marked impact on Arctic fjords and other nearshore areas. These form a productive zone that is vital for both Arctic biodiversity and local communities, rendering the understanding of Arctic coastal ecosystem change from a long-term perspective crucial.
This is a joint session of the PAGES working groups ACME and MARDI, which both aim at assessing and refining (coastal) marine biogenic proxies, such as diatoms – a special focus of MARDI – dinoflagellate cysts, foraminifera, highly branched isoprenoid (HBI) lipids and sedimentary ancient DNA (sedaDNA). A central objective of the two groups is to promote a leap forward in the accuracy of Arctic marine paleo reconstructions, both qualitative and quantitative, that are central for understanding climate-cryosphere-biosphere interactions in the region at relevant timescales.
We welcome contributions that deepen our understanding of marine biogenic proxy behaviour and/or Arctic coastal change.

This open session invites contributions in the various fields of past global changes, which do not fit into the specialized sessions. In particular we welcome presentations regarding (i) data - model comparison and methodologies thereof, methods and applications of data assimilation and paleo-reanalysis, (ii) novel approaches in Data Science and applications of artificial intelligence and machine learning in paleoscience, and (iii) other fields of PAGES science that do not fit into any other session.