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.

Is the climate warming? Is the hydrological cycle intensifying? Is the climate becoming more variable or extreme? Is the chemical composition of the atmosphere changing? Is the solar irradiance constant? Answers to these questions are fundamental to understanding, predicting, and assessing climate on time scales ranging from weeks to a century. Atmospheric, oceanic, and environmental scientists have primarily relied on an ad-hoc collection of disparate environmental observational and data management systems to address these problems. But these systems were not designed to measure climate variations and, as a result, changes and variations of the earth system during the instrumental climate record is far from unequivocal. This book develops a framework from which a Global Climate Observing System, currently being discussed in international forums, can be implemented to monitor changes and variations of climate. Audience: Administrators, policy makers, professionals, graduate students, and others interested in learning how we can ensure a long-term climate record for application to national economic development and understanding ecosystem dynamics.

The author describes the stochastic (probabilistic) approach to the study of changes in the climate system. Climatic data and theoretical considerations suggest that a large part of climatic variation/variability has a random nature and can be analyzed using the theory of stochastic processes. This work summarizes the results of processing existing records of climatic parameters as well as appropriate theories: from the theory of random processes (based on the results of Kolmogorov and Yaglom) and Hasselmann's "stochastic climate model theory" to recently obtained results.

A profound knowledge of the past climate is vital for our understanding of global warming. The past 2000 years are both the period which is of most relevance to the next century and that for which there is the most evidence. High-resolution proxy records for this period are available from a variety of sources. Five sections consider dendroclimatology, ice cores, corals, historical records, lake varves, and other indicators. The final two sections cover the histories of various forcing factors and attempt to bring together records from a variety of sources and provide explanations.