The U.S. Climate Change Science Program (CCSP) coordinates the efforts of 13 federal agencies to understand why climate is changing, to improve predictions about how it will change in the future, and to use that information to assess impacts on human systems and ecosystems and to better support decision making. Evaluating Progress of the U.S. Climate Change Science Program is the first review of the CCSP's progress since the program was established in 2002. It lays out a method for evaluating the CCSP, and uses that method to assess the strengths and weaknesses of the entire program and to identify areas where progress has not met expectations. The committee found that the program has made good progress in documenting and understanding temperature trends and related environmental changes on a global scale, as well as in understanding the influence of human activities on these observed changes. The ability to predict future climate changes also has improved, but efforts to understand the impacts of such changes on society and analyze mitigation and adaptation strategies are still relatively immature. The program also has not met expectations in supporting decision making, studying regional impacts, and communicating with a wider group of stakeholders.

The U.S. Global Change Research Program (USGCRP) is an interagency program, established by the Global Change Research Act (GCRA) of 1990, mandated by Congress to "assist the Nation and the world to understand, assess, predict, and respond to human-induced and natural processes of global change". Since the USGCRP began, scientific understanding of global change has increased and the information needs of the nation have changed dramatically. A better understanding of what is changing and why can help decision makers in the public and private sectors cope with ongoing change. Accomplishments of the U.S. Global Change Research Program highlights the growth of global change science in the quarter century that the USGCRP has been in existence, and documents some of its contributions to that growth through its primary functions of interagency planning and coordination, and of synthesis of research and practice to inform decision making.

It is now widely accepted that adaptation will be necessary if we are to manage the risks posed by climate change. What we know about adaptation, however, is limited. While there is a well established body of scholarship proposing assessment approaches and explaining concepts, few studies have examined if and how adaptation is taking place at a national or regional level.

Across the United States, impacts of climate change are already evident. Heat waves have become more frequent and intense, cold extremes have become less frequent, and patterns of rainfall are likely changing. The proportion of precipitation that falls as rain rather than snow has increased across the western United States and Arctic sea ice has been reduced significantly. Sea level has been rising faster than at any time in recent history, threatening the natural and built environments on the coasts. Even if emissions of greenhouse gases were substantially reduced now, climate change and its resulting impacts would continue for some time to come. To date, decisions related to the management and protection of the nation's people, resources, and infrastructure have been based on records in the recent past, when climate was relatively stable. Adapting to the Impacts of Climate Change, part of the congressionally requested America's Climate Choices suite of studies, calls for a new paradigm-one that considers a range of possible future climate conditions and impacts that may be well outside the realm of past experience. Adaptation requires actions from many decision makers in federal, state, tribal, and local governments; the private sector; non-governmental organizations; and community groups. However, current efforts are hampered by a lack of solid information about the benefits, costs, and effectiveness of various adaptation options; climate information on regional and local scales; and a lack of coordination. Adapting to the Impacts of Climate Change calls for a national adaptation strategy that provides needed technical and scientific resources, incentives to begin adaptation planning, guidance across jurisdictions, shared lessons learned, and support of scientific research to expand knowledge of impacts and adaptation.

This National Research Council (NRC) report reviews a draft of the U.S. Climate Change Science Program (CCSP) Synthesis and Assessment Product 3.3, Weather and Climate Extremes in a Changing Climate, the 3rd in a series of 21 CCSP products addressing important topics related to climate change. The NRC report finds that the draft provides a good and thorough assessment of the important issues regarding extreme events over North America and how they may change in the context of a changing climate. The continuity and cohesion among the chapters could be improved by greater coordination among the chapter authorship teams, who should also ensure that the tone and scope of the chapters are consistent with the document's Abstract and Executive Summary. The authors should strive to consolidate the sections on tropical cyclones; however, the discussion of drought and ecological impacts could be expanded. Overall, the committee finds that the scope, content, and scientific rigor of the current draft provide a solid basis for the final version of Synthesis and Assessment Product 3.3.

This report reviews the U.S. Climate Change Science Program's new draft assessment product on characterizing and communicating uncertainty information for climate change decision making, one of 21 climate change assessment products that the program is developing to meet the requirements of the 1990 Global Change Research Act. Although the draft assessment is effective in discussing methods of characterizing uncertainty, it falls short in several ways. It is written for researchers involved in assessment efforts and will likely be of use to them, but does not address other key audiences, particularly policymakers, decision-makers, and members of the media and general public. In addition, it does not assess the full range of "best practice approaches" for characterizing, incorporating, and communicating uncertainty. These weaknesses were due in part to a change in the prospectus after the process had begun to include new target audiences and a different scope of work. It will take a substantial revision of the current draft or production of a companion document, both requiring additional authors, to address these issues.