Climate change is occurring, is caused largely by human activities, and poses significant risks for-and in many cases is already affecting-a broad range of human and natural systems. The compelling case for these conclusions is provided in Advancing the Science of Climate Change, part of a congressionally requested suite of studies known as America's Climate Choices. While noting that there is always more to learn and that the scientific process is never closed, the book shows that hypotheses about climate change are supported by multiple lines of evidence and have stood firm in the face of serious debate and careful evaluation of alternative explanations. As decision makers respond to these risks, the nation's scientific enterprise can contribute through research that improves understanding of the causes and consequences of climate change and also is useful to decision makers at the local, regional, national, and international levels. The book identifies decisions being made in 12 sectors, ranging from agriculture to transportation, to identify decisions being made in response to climate change. Advancing the Science of Climate Change calls for a single federal entity or program to coordinate a national, multidisciplinary research effort aimed at improving both understanding and responses to climate change. Seven cross-cutting research themes are identified to support this scientific enterprise. In addition, leaders of federal climate research should redouble efforts to deploy a comprehensive climate observing system, improve climate models and other analytical tools, invest in human capital, and improve linkages between research and decisions by forming partnerships with action-oriented programs.

The Mediterranean region contains a diverse and interesting climate ranging from areas with permanent glaciers to areas of subtropical, semiarid regions. The region is potentially sensitive to climate change and its progress has environmental, social, and economic implications within and beyond the region. Produced by the Mediterranean Climate Variability and Predictability Research Networking Project, this book reviews the evolution of the Mediterranean climate over the past two millennia with projections further into the twenty-first century as well as examining in detail various aspects of the Mediterranean region's climate including evolution, atmospheric variables, and oceanic and land elements. Integrated with this, the book also considers the social and economic problems or vulnerabilities associated with the region. Written and reviewed by multiple researchers to ensure a high level of information presented clearly, Mediterranean Climate Variables will be an invaluable source of information for geologists, oceanographers, and anyone interested in learning more about the Mediterranean climate. Written by leading experts in the field Presents clear, compelling, and concise evidence Includes the latest thinking in Mediterranean climate research

Climate change poses many challenges that affect society and the natural world. With these challenges, however, come opportunities to respond. By taking steps to adapt to and mitigate climate change, the risks to society and the impacts of continued climate change can be lessened. The National Climate Assessment, coordinated by the U.S. Global Change Research Program, is a mandated report intended to inform response decisions. Required to be developed every four years, these reports provide the most comprehensive and up-to-date evaluation of climate change impacts available for the United States, making them a unique and important climate change document. The draft Fourth National Climate Assessment (NCA4) report reviewed here addresses a wide range of topics of high importance to the United States and society more broadly, extending from human health and community well-being, to the built environment, to businesses and economies, to ecosystems and natural resources. This report evaluates the draft NCA4 to determine if it meets the requirements of the federal mandate, whether it provides accurate information grounded in the scientific literature, and whether it effectively communicates climate science, impacts, and responses for general audiences including the public, decision makers, and other stakeholders.

The climate record for the past 100,000 years clearly indicates that the climate system has undergone periodic-and often extreme-shifts, sometimes in as little as a decade or less. The causes of abrupt climate changes have not been clearly established, but the triggering of events is likely to be the result of multiple natural processes. Abrupt climate changes of the magnitude seen in the past would have far-reaching implications for human society and ecosystems, including major impacts on energy consumption and water supply demands. Could such a change happen again? Are human activities exacerbating the likelihood of abrupt climate change? What are the potential societal consequences of such a change? Abrupt Climate Change: Inevitable Surprises looks at the current scientific evidence and theoretical understanding to describe what is currently known about abrupt climate change, including patterns and magnitudes, mechanisms, and probability of occurrence. It identifies critical knowledge gaps concerning the potential for future abrupt changes, including those aspects of change most important to society and economies, and outlines a research strategy to close those gaps. Based on the best and most current research available, this book surveys the history of climate change and makes a series of specific recommendations for the future.

The warming of the Earth has been the subject of intense debate and concern for many scientists, policy-makers, and citizens for at least the past decade. Climate Change Science: An Analysis of Some Key Questions, a new report by a committee of the National Research Council, characterizes the global warming trend over the last 100 years, and examines what may be in store for the 21st century and the extent to which warming may be attributable to human activity.

A top priority in climate research is obtaining broad-extent and long-term data to support analyses of historical patterns and trends, and for model development and evaluation. Along with directly measured climate data from the present and recent past, it is important to obtain estimates of long past climate variations spanning multiple centuries and millennia. These longer time perspectives are needed for assessing the unusualness of recent climate changes, as well as for providing insight on the range, variation and overall dynamics of the climate system over time spans exceeding available records from instruments, such as rain gauges and thermometers. Tree rings have become increasingly valuable in providing this long-term information because extensive data networks have been developed in temperate and boreal zones of the Earth, and quantitative methods for analyzing these data have advanced. Tree rings are among the most useful paleoclimate information sources available because they provide a high degree of chronological accuracy, high replication, and extensive spatial coverage spanning recent centuries. With the expansion and extension of tree-ring data and analytical capacity new climatic insights from tree rings are being used in a variety of applications, including for interpretation of past changes in ecosystems and human societies. This volume presents an overview of the current state of dendroclimatology, its contributions over the last 30 years, and its future potential. The material included is useful not only to those who generate tree-ring records of past climate-dendroclimatologists, but also to users of their results-climatologists, hydrologists, ecologists and archeologists. ‘With the pressing climatic questions of the 21st century demanding a deeper understanding of the climate system and our impact upon it, this thoughtful volume comes at critical moment. It will be of fundamental importance in not only guiding researchers, but in educating scientists and the interested lay person on the both incredible power and potential pitfalls of reconstructing climate using tree-ring analysis.’, Glen M. MacDonald, UCLA Institute of the Environment, CA, USA ‘This is an up-to-date treatment of all branches of tree-ring science, by the world’s experts in the field, reminding us that tree rings are the most important source of proxy data on climate change. Should be read by all budding dendrochronology scientists.’, Alan Robock, Rutgers University, NJ, USA

Climate change is occurring. It is very likely caused by the emission of greenhouse gases from human activities, and poses significant risks for a range of human and natural systems. And these emissions continue to increase, which will result in further change and greater risks. America's Climate Choices makes the case that the environmental, economic, and humanitarian risks posed by climate change indicate a pressing need for substantial action now to limit the magnitude of climate change and to prepare for adapting to its impacts. Although there is some uncertainty about future risk, acting now will reduce the risks posed by climate change and the pressure to make larger, more rapid, and potentially more expensive reductions later. Most actions taken to reduce vulnerability to climate change impacts are common sense investments that will offer protection against natural climate variations and extreme events. In addition, crucial investment decisions made now about equipment and infrastructure can "lock in" commitments to greenhouse gas emissions for decades to come. Finally, while it may be possible to scale back or reverse many responses to climate change, it is difficult or impossible to "undo" climate change, once manifested. Current efforts of local, state, and private-sector actors are important, but not likely to yield progress comparable to what could be achieved with the addition of strong federal policies that establish coherent national goals and incentives, and that promote strong U.S. engagement in international-level response efforts. The inherent complexities and uncertainties of climate change are best met by applying an iterative risk management framework and making efforts to significantly reduce greenhouse gas emissions; prepare for adapting to impacts; invest in scientific research, technology development, and information systems; and facilitate engagement between scientific and technical experts and the many types of stakeholders making America's climate choices.

Global climate change is one of America's most significant long-term policy challenges. Human activity-especially the use of fossil fuels, industrial processes, livestock production, waste disposal, and land use change-is affecting global average temperatures, snow and ice cover, sea-level, ocean acidity, growing seasons and precipitation patterns, ecosystems, and human health. Climate-related decisions are being carried out by almost every agency of the federal government, as well as many state and local government leaders and agencies, businesses and individual citizens. Decision makers must contend with the availability and quality of information, the efficacy of proposed solutions, the unanticipated consequences resulting from decisions, the challenge of implementing chosen actions, and must consider how to sustain the action over time and respond to new information. Informing an Effective Response to Climate Change, a volume in the America's Climate Choices series, describes and assesses different activities, products, strategies, and tools for informing decision makers about climate change and helping them plan and execute effective, integrated responses. It discusses who is making decisions (on the local, state, and national levels), who should be providing information to make decisions, and how that information should be provided. It covers all levels of decision making, including international, state, and individual decision making. While most existing research has focused on the physical aspect of climate change, Informing an Effective Response to Climate Change employs theory and case study to describe the efforts undertaken so far, and to guide the development of future decision-making resources. Informing an Effective Response to Climate Change offers much-needed guidance to those creating public policy and assists in implementing that policy. The information presented in this book will be invaluable to the research community, especially social scientists studying climate change; practitioners of decision-making assistance, including advocacy organizations, non-profits, and government agencies; and college-level teachers and students.

Summarizes the science of climate change and impacts on the United States, for the public and policymakers.

In Resilience: The Science of Adaptation to Climate Change leading experts analyze and question ongoing adaptation interventions. Contributions span different disciplinary perspectives, from law to engineering, and cover different regions from Africa to the Pacific. Chapters assess the need for adaptation, highlighting climate change impacts such as sea level rise, increases in temperature, changing hydrological variability, and threats to food security. The book then discusses the state of global legislation and means of tracking progress. It reviews ways to build resilience in a range of contexts— from the Arctic, to small island states, to urban areas, across food and energy systems. Critical tools for adaptation planning are highlighted - from social capital and ethics, to decision support systems, to innovative finance and risk transfer mechanisms. Controversies related to geoengineering and migration are also discussed. This book is an indispensable resource for scientists, practitioners, and policy makers working in climate change adaptation, sustainable development, ecosystem management, and urban planning. - Provides a summary of tools and methods used in adaptation including recent innovations - Includes chapters from a diverse range of authors from academic institutions, humanitarian organizations, and the United Nations - Evaluates adaptation options, highlighting gaps in knowledge where further research or new tools are needed