The Climate Prediction Project Global Climate Information for Regional Adaptation and Decision-Making in the 21st Century Challenge The world recognizes that the threat of global climate change is one of the most important problems facing humanity. To cope with the consequences of climate change, the peoples, governments, and economies of the world must develop mitigation and adaptation strategies, which will require investments of trillions of dollars. The development of science-based adaptation and mitigation strategies will only be possible through a revolution in regional climate predictions. The Summit The World Modeling Summit for Climate Prediction was organized to develop a strategy to revolutionize prediction of the climate through the 21st century to help address the threat of global climate change. Summit Declaration 1. Improved prediction of the changes in the statistics of regional climate, especially of extreme events and high-impact weather, are required to assess the impacts of climate change and variations, and to develop adaptive strategies to ameliorate their effects on water resources, food security, energy, transport, coastal integrity, environment and health. Summit Declaration 2. Our current inadequacy in the provision of robust estimates of the risk to society, particularly from possible catastrophic changes in regional climate, is strongly influenced by limitations in computer power and the size of the scientific workforce. Summit Declaration 3. Climate prediction is among the most computationally demanding problems in science. It is both necessary and possible to revolutionize climate prediction: necessary because of the grand challenge posed by the changing climate, and possible building on the past accomplishments of prediction of weather and climate. However, the scientific expertise and the computing capability is not available in any single nation, and a comprehensive international effort is essential. Investing today in climate science will lead to significantly reduced costs of coping with climate change tomorrow. Summit Declaration 4. A Climate Prediction Project coordinated by WCRP, in collaboration with WWRP and the IGBP and involving the national weather and climate centers should be initiated to provide global climate information for regional adaptation and decision-making in the 21st century. Summit Declaration 5. As a part of the Climate Prediction Project, and in addition to enhancing the capacity of the world’s existing national climate research centers, a World Climate Research Facility (WCRF) for climate prediction should be established that will enable the national centers to accelerate progress in improving operational climate prediction at decadal to multidecadal lead times, enhancing understanding of the climate system, building global capacity, developing a trained scientific workforce, and engaging the global user community. The WCRF will argue for sustained, long-term, global observations that are needed to initialize, constrain and verify the models. An important component of the WCRF will be an archive of observations and model data with appropriate user interface and knowledge-discovery tools for diagnostic tests. Summit Declaration 6. The central component of the WCRF will be one or more dedicated high-end computing facilities that will enable the revolution in climate prediction by supporting the model resolution and complexity required for the most advanced and reliable representations of the climate system that technology and our scientific understanding of the problem can deliver. This computing capability, with systems at least 10,000 times more powerful than the currently available computers, is vital for regional climate predictions to underpin mitigation policies and local and regional adaptation needs with robust estimates of risk. The computing capability will help advance our understanding of the processes responsible for climate variability and predictability, and provide a quantum leap in the exploration of the limits in our ability to reliably predict climate with a level of detail and complexity that is not possible at the national centers. It will also make it possible to bring to bear the latest and most innovative computer technology on the climate change problem, and provide a common modeling framework through an international computing laboratory and make it possible to conduct specialized experiments to advise decision-making in adaptation, mitigation. This project will permit scientists to strive towards kilometer-scale modeling of the global climate system, which will particularly benefit the simulation and prediction of tropical climate, helping many of the world’s developing countries that are especially vulnerable to climate change. Summit Declaration 7. The WCRF will make it possible for the first time to deliver climate predictions with a reliable estimate of their uncertainty. To estimate the quality of a climate prediction requires an assessment of how accurately we know the current phase of natural climate variability, on which anthropogenic climate change is superimposed. But also the WCRF will enable the climate research community to assess how model uncertainties limit the skill of climate predictions. All elements of estimating the uncertainty in climate predictions pose an extreme burden on computing resources but also on the availability of observational data. Summit Declaration 8. The methodology of initializing weather and short-term climate prediction models with observations must be seamlessly extended to predictions of decadal variations and climate change. The understanding and representation of physical and biogeochemical processes and feedbacks must be improved to make reliable centennial projections. Summit Declaration 9. It may be possible that the WCRF will be funded in different ways, e.g., through publicprivate partnerships with corporate and foundation resources and through governmental treaties and agreements. Summit Declaration The Climate Prediction Project has the potential to help humanity cope with the consequences of climate change. The lasting legacy of the Project will be to help the citizens of the world in the 21st century.