The publication in 1972 of “The Limits to Growth” by the Club of Rome marked the emergence of a public awareness about collective perils associated to the sustainability of our development. Since then, citizens and politicians were confronted to a never ending list of environmental problems: nuclear wastes, genetically modified organisms, climate change, biodiversity, … This debate has recently culminated with the publication of three reports. On one side, the Copenhagen Consensus (Lomborg (2004)) put top priority to public programs yielding immediate benefits (fighting malaria and AIDS, improving water supply, ...), and rejected the idea to invest much in the prevention of global warming. On the other side, the Stern Review (Stern -2007) and the fourth report of the IPPC (IPCC (2008)) put a tremendous pressure for acting quickly and heavily against global warming. The absence of consensus among the experts on this question is translated in the public debate and in the public actions, notably with the limited success of the Kyoto protocol.

A striking aspect of the recent debate on the climate change is the transfer of the hottest scientific challenges from the so-called hard sciences (climatology, oceanography, chemistry,…) to social sciences and humanities (SSH). Still, the SSH community is much divided on the way to approach long-term environmental challenges, given what hard sciences tell them. The difficulty to determine an efficient public policy for the environment may be explained by several factors. First, for many of the underlying long term environmental risks, there is still a lot of scientific uncertainty about their intensity and their impact on the welfare of future generations. Moreover, people have heterogeneous beliefs and preferences about the probabilities of really catastrophic consequences of various environmental policies. How can the power of “visions” be utilized? What “welfare measures” beyond GDP are desired and possible to capture environmental impacts? Second, based on these uncertainties, people disagree about whether we should wait or not to get better information before implementing strong actions. How and where should the precautionary principle be implemented, without hindering necessary changes? Third, there is much disagreement about how much effort should be done to improve the environment available for future generations. Cutting-edge science addressing these questions works interdisciplinary, between social sciences, humanities, and natural sciences and employs the best of their findings and minds.

The aim of this conference is to discuss a unified and interdisciplinary framework to study the collective challenges associated to climate change, and to make policy recommendations. We will discuss various general concepts such as “sustainable development”, “corporate social responsibility” and “precautionary principle”, which often have different meanings in different disciplines of SSH.

At the occasion of the French Presidency of the European Union, an EU-wide conference is organized on that topic, which offers a great opportunity “to make the case” for SSH sciences.
Leading SSH scientists will be present, as well as practitioners and the media. The building blocks for the conference are the following:
• Providing general background on SSH contributions to issues of (global) environmental change (GEC).
• Cases should be discussed where SSH have been both successful in influencing the common research agenda on GEC as well as political decision making processes.
• “Cross-cutting themes” such as uncertainties/ambiguities, coupled socio-ecological systems, multi-level governance, and transdisciplinary research as well as opportunities and challenges of science-policy interactions will feature prominently throughout the conference.
• Conclusions, identification of findings, new research questions and concrete next steps.

Roundtable 1: Sustainable development
The concept of sustainable development is at the heart of the public debate on environmental policies, and there is much confusion on its meaning. How much sacrifice should we do in order to improve the welfare of future generations, or to guarantee equal opportunities to selffulfilment and happiness? Which are the most efficient strategies favouring sustainability? Should we reform the way our societies are organized to attain it? To which extent do ourperceptions of human societies in the distant future shape our current environmental policies?

Roundtable 2: Uncertainties, knowledge and perceptions
Changing human behaviour is a pressing issue of these days and good science is needed to do such changes well-informed. What kind of changes can we expect from individuals, e.g. as consumers, as a function of the uncertainties that they perceived and of their incomplete knowledge? Generally, the “tools” at hand are diverse and certainly not everybody favours everything, reaching from monetary incentives to educational programmes, “persuasion literature” or moral values. Theories about knowledge and social learning, on the other hand, put much emphasis on participatory processes and communicative aspects of social challenges bound to environmental change. Furthermore, the (non-) existence of insurances, legislations or conventions are institutional arrangements with great impact on humans behaviour. To simulate social situations to better understand societal changes is as important as providing people with the opportunity to actively engage with “their futures” and particularly in research about it.

Roundtable 3: Evaluation of environmental impacts
The state-of-the-art methodology to evaluate an environmental project is based on the benefit/cost analysis in which the net present value of the future monetized benefits is compared to the cost of the project. For example, much effort by the SSH community has been devoted to use this methodology in the case the reduction of emissions of carbon dioxide with much disagreement among experts. Similar attempts to evaluate environmental policy in favour of the biodiversity, or of the moratorium on genetically modified organisms for example, led to similar ambiguous conclusions. This may be due to diverging methodologies or unequal treatments of key dimensions, such as discounting, uncertainty, and the valuation of various impacts (lost lives, environmental assets,…).

Roundtable 4: The governance of climate change policy
The climate change problem is a global challenge, which requires a global strategy. However, it is affected by the classical free rider problem at a level never attained before: everyone has an interest in relying on others to bear the burden of the effort. The governance of climate question is thus a crucial question, with ethical and socio-economic issues. It is made even more complex by the presence of winners and losers from climate changes, by the uncertainty surrounding both the impacts in the distant future and the speed of technological progress in green technologies, or by disagreements on the relative efficiency of tax schemes and markets for emission permits.

Roundtable 5: Policy Implications for Europe
Public decision makers will bring their views about the governance of climate change policy at the national and European levels.