The effects of climate change on society depend on changes in both the climate and in society over many decades. For example, the impacts of climate change on coastal communities in 2070 depend not only on changes in sea level and storm behavior but also on changes in population distributions and land uses over the period between now and then, including voluntary responses in anticipation of future threats. This international workshop will consider the current state of the science and will develop improved methods for describing the long-term social and economic future. The purpose is to anlyze the potential impacts of climate change and consider alternative responses.
Projecting more than a few decades into the future is usually treated as beyond the capability of demographers and other social scientists who work on socioeconomic and technological change. Ongoing global climate change challenges these communities to stretch beyond the usual limits of their willingness to project and to develop methods of integrated analysis that can put long-term decisions about how to respond to climate change on a solider scientific foundation. The workshop will bring together several research communities that work on parts of the problem but that are not in close coordination, as well as researchers from both high- and low-income countries who have addressed the problem in fundamentally different ways, to discuss ways to meet the challenge. It would encourage them to consider new analytical approaches and would stimulate further work and collaborations to integrate impact projections from physical models; scientifically credible descriptions of future demographic, economic, and social change; and potential mitigation and adaptation responses in anticipation of such impacts. Such integrated scenarios are important for long-range planning to reduce vulnerability to climate change. They call the attention of decision makers to the places and populations at greatest risk and help identify response options that will be robust in many plausible futures. The workshop will help advance analysis of the possible impacts of long-term global climate change and better inform responses to climate change.
The most serious impacts of climate change will occur at future times, when the affected social and economic systems will be different from what they are now. This project organized an international workshop in response to increasing recognition by the scientific community that improved socioeconomic scenarios are needed to understand climate change vulnerabilities and adaptive capacity. The need is pressing for researchers working on projecting and considering the long-term impacts of climate change and for informing policy choices at national and international levels. The objectives of the workshop were to review the state of science for considering socioeconomic changes over long time frames; clarify definitions and concepts to facilitate communication across research communities; brainstorm about driving forces and key uncertainties that will affect climate change impacts, adaptation, vulnerability, and mitigation in the future; and consider research needs and the elements of a strategy for describing socioeconomic and environmental futures for climate change research and assessment. The participants reviewed narrative and quantitative methods from a range of disciplines for developing long-term scenarios of socioeconomic futures; identified key factors that might influence adaptation, mitigation, and the environment in the coming decades and that need to be covered in future scenarios; discussed a new process for scenario development that uses "representative concentration pathways" describing possible futures of the greenhouse gas concentrations that drive climate change and examined the range of socioeconomic assumptions in the models that produce those pathways. They also shared prior experience in the use of narratives and scenarios. Workshop participants explored the current state of science in scenario development and application and discussed opportunities for a next round of climate change assessments, including those of the Intergovernmental Panel on Climate Change and the U.S. Global Change Research Program. They identified a number of research needs and opportunities that are described in the project report. For example, they a noted a need for geographically "nested" socioeconomic scenarios for local and regional vulnerability assessments with different degrees of coupling to the global context as represented in the concentratrion pathways. The project did not attempt to come to consensus on recommendations or a specific research agenda.
