This report provides prioritization frameworks in accommodating projected future weather and climate extremes for policy makers and engineers involved in infrastructure planning and design.

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 Transportation Research Board (TRB) and the Division on Earth and Life Studies (DELS) have released the pre-publication version of TRB Special Report 290, The Potential Impacts of Climate Change on U.S. Transportation, which explores the consequences of climate change for U.S. transportation infrastructure and operations. The report provides an overview of the scientific consensus on the current and future climate changes of particular relevance to U.S. transportation, including the limits of present scientific understanding as to their precise timing, magnitude, and geographic location; identifies potential impacts on U.S. transportation and adaptation options; and offers recommendations for both research and actions that can be taken to prepare for climate change. The book also summarizes previous work on strategies for reducing transportation-related emissions of carbon dioxide--the primary greenhouse gas--that contribute to climate change. Five commissioned papers used by the committee to help develop the report, a summary of the report, and a National Academies press release associated with the report are available online. DELS, like TRB, is a division of the National Academies, which include the National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council.

As climate has warmed over recent years, a new pattern of more frequent and more intense weather events has unfolded across the globe. Climate models simulate such changes in extreme events, and some of the reasons for the changes are well understood. Warming increases the likelihood of extremely hot days and nights, favors increased atmospheric moisture that may result in more frequent heavy rainfall and snowfall, and leads to evaporation that can exacerbate droughts. Even with evidence of these broad trends, scientists cautioned in the past that individual weather events couldn't be attributed to climate change. Now, with advances in understanding the climate science behind extreme events and the science of extreme event attribution, such blanket statements may not be accurate. The relatively young science of extreme event attribution seeks to tease out the influence of human-cause climate change from other factors, such as natural sources of variability like El Niño, as contributors to individual extreme events. Event attribution can answer questions about how much climate change influenced the probability or intensity of a specific type of weather event. As event attribution capabilities improve, they could help inform choices about assessing and managing risk, and in guiding climate adaptation strategies. This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities.

Climate extremes often imply significant impacts on human and natural systems, and these extreme events are anticipated to be among the potentially most harmful consequences of a changing climate. However, while extreme event impacts are increasingly recognized, methodologies to address such impacts and the degree of our understanding and prediction capabilities vary widely among different sectors and disciplines. Moreover, traditional climate extreme indices and large-scale multi-model intercomparisons that are used for future projections of extreme events and associated impacts often fall short in capturing the full complexity of impact systems. Climate Extremes and Their Implications for Impact and Risk Assessment describes challenges, opportunities and methodologies for the analysis of the impacts of climate extremes across various sectors to support their impact and risk assessment. It thereby also facilitates cross-sectoral and cross-disciplinary discussions and exchange among climate and impact scientists. The sectors covered include agriculture, terrestrial ecosystems, human health, transport, conflict, and more broadly covering the human-environment nexus. The book concludes with an outlook on the need for more transdisciplinary work and international collaboration between scientists and practitioners to address emergent risks and extreme events towards risk reduction and strengthened societal resilience.

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

Extreme weather and climate events, interacting with exposed and vulnerable human and natural systems, can lead to disasters. This Special Report explores the social as well as physical dimensions of weather- and climate-related disasters, considering opportunities for managing risks at local to international scales. SREX was approved and accepted by the Intergovernmental Panel on Climate Change (IPCC) on 18 November 2011 in Kampala, Uganda.