Mountain glaciers and ice caps are major contributors to sea-level rise and have large impacts on water balance of local basins. This is a general session on glaciers and ice caps where the relationship to climate forms a particular focus. The IPCC AR5 of Working Group 1 covers Earths Glaciers and Ice Caps outside the ice sheets under the heading of Glaciers and shows that, despite much progress recently provided by the community, we are still left with substantial unknowns. We need to acquire more data, both from new fieldwork and release of unpublished data from prior years on mass changes of glaciers and ice caps from all regions of the world. We need to improve the understanding of the processes behind the changes, and we need to improve the application of models of different complexity. We welcome presentations on all aspects of mass changes; current, past and future changes based on field observations, remote sensing and modeling. Studies of physical processes controlling accumulation and ablation including calving and submarine melting, are especially welcome.

Studies of ice extent, volume and dynamics during former glaciations are important for understanding past climates and evolution of the Earth’s surface, and also provide analogies for present-day ice sheets and their subglacial environments. This includes observations of glacial erosion, glacial transport and deposition of sediments, formation of fjords and their relation to ice streams, evidence for migration of ice divides, former locations of subglacial lakes, relations between high geothermal heat flow, basal ice melt and rapid ice flow, and other aspects of paleo glacier extent and behaviour. This session will bring together the interdisciplinary scientific community working on former ice covers from the perspectives of glacial geomorphology, quaternary geology, and numerical modeling. It will provide a forum in which field-based reconstructions and model-based simulations can be compared and contrasted. We particularly welcome contributions that shed light on ancient and more recent glaciations on Earth and their interaction with other components of the Earth System.

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

The millennial-scale variability associated with Dansgaard-Oeschger (D-O) cycles during the last glacial is known to have affected the climate system on a global scale. New high-resolution sediment and ice core proxy records document in increasing detail local and global variability of ice sheets, sea ice, as well as oceanic and atmospheric circulation during the D-O cycles. In addition, insights into the dynamics of the coupled ocean-cryosphere-atmosphere system during the millennial-scale climate cycles are emerging from improved model simulations. Documenting the precise timing and sequence of events in proxy records and capturing the processes responsible for the global pattern of rapid climate changes, which stretch from Greenland to Antarctica, remains a major challenge. However, understanding the underlying dynamics will provide fundamental information on the stability of the global climate system. In this interdisciplinary session, we welcome proxy- and model-based research that tests hypotheses on causes and processes behind the D-O events and helps understanding past, present and future changes to the climate system. The session is hosted by the ERC synergy project ice2ice.

Solicited talks include:
Oeschger medal lecture by Edward Brook, Oregon State University
Marlene Klockmann, Helmholtz-Zentrum Geesthacht Centre
Bradley Markle, University of Washington

The mid-Pleistocene Transition (MPT) is a crucial changes in climate dynamics, leading us into our current regime of long, asymmetric glacial cycles. However, evidence about the differences in how climate behaved before and after the MPT remains sparse and we also lack evidence to decide between theories that aim to explain the MPT. Here we hope to gather new datasets that compare climate on either side of the MPT or that offer new evidence about glacial cycles before it. Modelling and conceptual work about the causes of the MPT are also wlecome. Finally we would like to hear about work that paves the way for new projects, including plans and methodologies to obtain pre-MPT ice cores such as (but not limited to) the IPICS Oldest Ice challenge, like Beyond EPICA and other endeavours.

The Tibetan Plateau and surrounding mountain regions, known as the Third Pole, cover an area of > 5 million km2 and are considered to be the water tower of Asia. The Pan Third Pole expands on both the north-south and the east-west directions, going across the Tibetan Plateau, Pamir, Hindu Kush, Iran Plateau, Caucasian and Carpathian, and covering an area of about 20 million km2. Like the Arctic and Antarctica, the Pan Third Pole’s environment is extremely sensitive to global climate change. In recent years, scientists from around the globe have increased observational, remote sensing and numerical modeling research related to the Pan Third Pole in an effort to quantify and predict past, current and future scenarios. Co-sponsored by TPE (www.tpe.ac.cn), this session is dedicated to studies of Pan Third Pole atmosphere, cryosphere, hydrosphere, and biosphere and their interactions with global change. Related contributions are welcomed.

Mountains cover approximately one quarter of the total land surface on the planet, and a significant fraction of the world’s population lives in their vicinity. Orography critically affects weather and climate processes at all scales and, in connection with factors such as land-cover heterogeneity, is responsible for high spatial variability in mountain weather and climate.

Due to this high complexity, monitoring and modeling the atmosphere and the other components of the climate system in mountain regions is challenging both at short (meteorological) and long (climatological) time-scales. This session is devoted to the better understanding of weather and climate processes in mountain and high-elevation areas around the globe, as well as their modification induced by global environmental change.

We welcome contributions describing the influence of mountains on the atmosphere on meteorological time-scales, including terrain-induced airflow, orographic precipitation, land-atmosphere exchange over mountains, forecasting and predictability of mountain weather. Furthermore we invite studies that investigate climate processes and climate change in mountain areas and its impacts on dependent systems, based on monitoring and modeling activities. Particularly welcome are contributions that merge various sources of information and reach across disciplinary borders (atmospheric, hydrological, cryospheric, ecological and social sciences).

A planned outcome of this session is a summary document providing a mountains perspective and input for the IPCC Sixth Assessment Report, more specifically for Working Group I report on the Physical Sciences Basis and the cross-chapter paper on 'Mountains', which is flagged for the Working Group II report. This summary document is organized and supported by the Mountain Research Initiative (MRI).

The Arctic sea ice and high latitude atmosphere and oceans have experienced significant changes over the modern observational era. The polar climate is crucial for the Earth’s energy and water budget, and its variability and change have direct socio-economic and ecological impacts. Thus, understanding high-latitude variability and improving predictions of high latitude climate is highly important for society. Predictability studies indicate that decadal to multi-decadal variations in the oceans and sub-seasonal to multi-year sea ice variations are the largest sources of predictability in high latitudes. However, dynamical model predictions are not yet in the position to provide us with accurate predictions of the polar climate. Main reasons for this are the lack of observations in high latitudes, insufficient initialization methods and shortcomings of climate models in representing some of the important climate processes in high latitudes.
This session aims for a better understanding and better representation of the mechanisms that control high latitude climate variability and predictability in both hemispheres at sub-seasonal to multi-decadal time-scales in past, recent and future climates. Further, the session aims to discuss ongoing efforts to improve climate predictions at high latitudes at various time scales (as e.g. usage of additional observations for initialization, improved initialization methods, impact of higher resolution, improved parameterizations) and potential teleconnections of high latitude climate with lower latitude climate. We also aim to link polar climate variability and predictions to potential ecologocal and socio-economic impacts and encourage submissions on this topic.
This session offers the possibility to present results from the ongoing projects and research efforts on the topic of high-latitude climate variability and prediction, including, but not limited to Year of Polar Prediction (YOPP), and the ARCPATH-project (Arctic Climate Predictions - Pathways to Resilient, Sustainable Societies).

Tipping elements in the Earth's climate system are continental-scale subsystems that are characterized by a threshold behavior. It has been suggested that these include biosphere components (e.g. the Amazon rainforest and coral reefs), cryosphere components (e.g. the Greenland and Antarctic ice sheets) and large-scale atmospheric and oceanic circulations (e.g. the thermohaline circulation, ENSO and Indian summer monsoon). Once operating near a threshold or tipping point, these components can transgress into a qualitatively different state by small external perturbations. The large-scale environmental consequences could impact the livelihoods of millions of people.

In this session, we aim to bring together experts presenting and discussing the state-of-the-art research on tipping elements in the Earth's climate system, both in empirical data and numerical modelling of past, present and future climate. Among other topics, issues to be addressed in this session include critical thresholds for specific tipping elements, typical time scales of tipping, interactions and feedbacks between tipping elements, the potential for tipping cascades as well as environmental and socio-economic impacts of tipping.