Co-conveners : A. Robock, Rutgers University, Department of Environmental Sciences, New Brunswick - USA; M-A. Sicre, CNRS LOCEAN, Sorbonne universit�s, Paris, France

An unprecedented joint paleo-data and -modeling community effort has recently been undertaken by the IGBP-PAGES 2k network to compile and interpret high-resolution paleo climate records over the past 2000 years (CE, Common Era). From this analysis of climate variability and sensitivity to external forcings, volcanic eruptions have emerged as major drivers of climate. In this session, we welcome contributions on climate variability during the Common Era, using observations, proxy- or modeling-based approaches, or a combination of both. We also encourage discussions on new developments for data selection and climate reconstruction techniques, and new standards for data sharing and archival, with an emphasis on research addressing the role of volcanic forcing in modulating climate variability. Studies aiming at incorporating effects of volcanic eruptions and other external forcing mechanisms in climate prediction models as well as addressing the effects of volcanic events and their climate impact on society, including impacts on agriculture, and social disruption, and how similar eruptions could impact current society.

Lead Conveners: JL. Fellous (COSPAR, Executive Director, Paris, France) ; C. Baker (NOAA/OAR/ARL/ATDD, Oak Ridge, USA)

The session will showcase the rich datasets used by the global Earth science community. It will assess which climate observations are made, what are the remaining gaps identified by the scientific community for better understanding climate processes and their impacts on ecosystems and human society. It will also evaluate the technical capacity to observe new variables, and discuss whether and how the list of Essential Climate Variables should be updated. The conveners also invite papers that cover topics that include design and implementation of National Climate Observing Networks and the use of climate observing networks for improved climate data and information.

Lead Convener: M. Siegert (Imperial College London, Grantham Institute, London - UK)

The major contribution to future sea level change is likely to come from melting of the polar ice sheets. Considerable uncertainty exists as to how Antarctica and Greenland will change in the coming decades, however, limiting our ability to predict sea level rise with certainty. In this session established information and new knowledge of global sea-level, based on measurements of both the Antarctic and Greenland ice sheets, and quantification of uncertainty, will be discussed to provide a state-of-art account of future sea level change, and the cryospheric response to climate and ocean warming.

Lead Convener: C. Stubenrauch (Laboratoire de M�t�orologie Dynamique, Universit� de Paris 6, Paris - France)

Water vapour is source of clouds and of precipitation. Condensation of water and dissipation of clouds / precipitation affects the atmospheric circulation through heat transfer. Therefore clouds play a dominant role in the energy and water cycles. The interaction of all components (including those with aerosols and land surface) leads to changes of these cycles in a changing climate.
Understanding of how sources of fresh water are to change in a changing climate is a grand challenge that must be addressed if we are to understand and predict changes to the planet�s water cycle and impacts of these changes. Underpinning this challenge is the need to observe and predict changes to precipitation within the evolving climate. A number of fundamental questions loom including how regional precipitation amount, type, spatial and temporal distribution, and intensity change within a changing global environment, what processes are most responsible for these changes and how these changes couple to and influence other components of the climate system and society

Co-conveners: M., LSCE, IPSL, Gif-sur-Yvette - France; F-M. Breon, IPSL, LSCE, Gif sur Yvette - France

This session is intended to present and discuss the current GHG observation networks and stations, its capabilities and limitations for the monitoring of Carbon fluxes and other GHG. Contributions about mitigation solution implying CO2, CH4 or other GHG are also welcome in the session.

Lead Conveners: A. Robock (Rutgers University, Department of Environmental Sciences, New Brunswick - USA); M.A. Sicre (CNRS LOCEAN, Sorbonne universités, Paris - France)

An unprecedented joint paleo-data and -modeling community effort has recently been undertaken by the IGBP-PAGES 2k network to compile and interpret high-resolution paleo climate records over the past 2000 years (CE, Common Era). From this analysis of climate variability and sensitivity to external forcings, volcanic eruptions have emerged as major drivers of climate. In this session, we welcome contributions on climate variability during the Common Era, using observations, proxy- or modeling-based approaches, or a combination of both. We also encourage discussions on new developments for data selection and climate reconstruction techniques, and new standards for data sharing and archival, with an emphasis on research addressing the role of volcanic forcing in modulating climate variability. Studies aiming at incorporating effects of volcanic eruptions and other external forcing mechanisms in climate prediction models as well as addressing the effects of volcanic events and their climate impact on society, including impacts on agriculture, and social disruption, and how similar eruptions could impact current society.

Lead Convener: H. Kreibich (German Research Centre for Geosciences, Section Hydrology, Potsdam - Germany)

Extreme hydrological events, particularly floods but also low flows and droughts, have huge economic and social impacts. Hazards and risks seem to have increased and further increases are expected due to global change.
These risks are the result of extreme hydrological events in combination with human activities and their feedbacks. These process interactions are complex and heterogeneous in space and time and difficult to understand and model on local, regional and global scales. The question is open, how the different drivers of change that act in a given catchment superimpose each other, and to which extent different drivers are responsible for changes in the hydrological cycle and in the risks due to hydrological extremes.
Thus, the main aim of this session is to present and jointly discuss results from various disciplines on the effects of climate and global change on hydrological extremes and their consequences at different time-scales and in various regions of the world. In bringing together experts from the natural hazards and climate change community we aim to advance the knowledge and scientific discourse on detection and attribution of changes as well as on modelling future changes.

Lead Conveners: D. Hauglustaine (LSCE-CNRS, Gif-sur-Yvette - France) ; T. Butler (Institute for Advanced Sustainability Studies, Potsdam - Germany)

Air quality and climate are closely linked. Climate change can alter levels of air pollution through changes to meteorology, affecting both atmospheric chemistry on the local scale, and long range transboundary transport of air pollution. Emissions of air pollutants and their precursors can also affect climate through their direct and indirect radiative forcing. Further efforts are needed to reduce air pollution concentrations and their harmful effects on the health of individuals. At the same time, policy makers are increasingly confronting the challenges of climate change adaptation and mitigation.
This session will explore the state of knowledge of the linkages between air quality and climate change. It will also address the pressing gaps remaining in knowledge and understanding of air quality and climate change health impact assessment at various scales. A special emphasis will be given to how air quality and health may be directly impacted by policies that aim to reduce greenhouse gas emissions and how climate-related changes in air quality could have important implications for human health, particularly in cities where urbanization and heat islands aggravate air quality problems.

Lead Conveners: C. Cudennec (IAHS, Allenvi, Agrocampus Ouest, Rennes - France); L. Longuevergne (CNRS, University Rennes 1, Geosciences Rennes, Rennes - France)

The freshwater cycle is a strong structural and functional driver linking processes, locations, scales, uses and hazards, and socio- institutional entities and dynamics. The freshwater cycle also provides a key interface between the atmosphere, the geosphere, the biosphere and the anthroposphere; and between the basic needs, especially for water, food, energy and health. Although the fundamental physics behind climate processes is rather straightforward, the impact of climate change on local water resources is difficult to quantify with limited uncertainty (IPCC 2014).
Two sessions will address these issues across the first days of the conference, with a conceptual progression from actual knowledge towards approaches to shape the future.
This first session will address the state of knowledge and uncertainties about the impact of climate change on hydrological processes and associated resources and hazards, the underlying complexity, and the major scientific challenge of de-convoluting the causal effects of climate change and other changes which impact on the hydrology, i.e. the issue of attribution as identified in the IPCC (2014) chapter on freshwater.

Lead Conveners: MY. Daire (CNRS, CReAAH Centre de Recherche en Arch�ologie, Arch�osciences, Histoire, Rennes - France); C. Sabbioni (Consiglio Nazionale delle Ricerche, Istituto di scienze del atmosfera e del clima, Bologna - Italy)

Climate change threatens Cultural Heritage materials outdoor and indoor both by extreme events (extreme winds and precipitations, flooding, heat waves, drought, pollution peaks) and slow changes (temperature, humidity, time of wetness, number of tropical nights and frost days). These slow changes are in strong or in weak correlation with air pollution. They lead to salt crystallization, freeze-thaw damage, submersion of monuments on littoral, swelling-shrinkage of expansive clay minerals in soils threatening the monument stability, biomass accumulation on surfaces in urban and rural areas, deterioration of wood and paper, pest infestation of collections�Coastal heritage in its broadest sense is an �at risk� resource faced with long-term erosion and the sudden damages and coastal managers have to moderate and deal with these impacts which can lead to the loss of coastal heritage. This heritage is essential to build our scientific knowledge and to assess the coastal evolution through the past millennium in order to enable more accurate predictions of future changes and their potential impacts. This session will explore the vulnerability of the threatened heritage and the way scientists may contribute to the building of scientifically based mitigation and adaptation in response to that threat.

Lead Convener: H. Le Treut ( Institut Pierre Simon Laplace, Paris - France)

The development of interdisciplinary models linking the representation of climate change with a variety of of impact processes has permitted an important progress in the capacity of the scientific community to address problems reflecting widely different societal concerns.

Lead Conveners: P. Lane (Archaeology & Ancient History, Uppsala - Sweden) ; B. Hazard (Institut Interdisciplinaire d'anthropologie du contemporain, Institut National des Sciences Humaines et Sociales - CNRS, Paris - France)

Drawing on diverse kinds of environmental, archaeological, archival and ethnographic data sets generated by the Resilience in East African Landscapes (REAL) project, we intend to illustrate the nature and character of the evolution of different regional socialecological systems over the last ca. 500 years, while also exploring how the political ecology of these landscapes has been transformed. To do this, we will compare and contrast the responses of various temporal and spatial dynamics of socio-ecological systems in East African mountain regions (such as around Mts Kilimanjaro and Kenya), semi-arid and arid lands and those recorded for various lakes and river-valley systems. We also aim to demonstrate how best to extract lessons from and knowledge of past practices, so as to improve the design of policies and programs meant to address the challenges of the future.