Introduction -- Study Charge, Scope, and Audience -- Why Climate Change Matters -- Study Approach and Key Issues -- Organization of the Report -- Understanding Climate Change -- Overview of Global Climate Change -- Climate Changes Relevant to U.S. Transportation -- Findings -- Impacts of Climate Change on Transportation -- Vulnerability of the Transportation System to Climate Change -- Potential Impacts by Transportation Mode -- Review of Assessments for Particular Areas or Regions -- Findings -- Annex 3-1: Potential Climate Changes and Impacts on Transportation -- Challenges to Response -- Decision Making in the Transportation Sector -- Challenges Posed by Climate Change -- A Decision Framework for Addressing Climate Change -- Findings -- Annex 4-1: Applying Probabilistic Risk Assessment to Climate Change and Transportation -- Meeting the Challenges -- Adaptation Strategies -- Crosscutting Issues -- Findings -- Annex 5-1A: Potential Climate Changes, Impacts on Land Transportation, and Adaptation Options -- Annex 5-1B: Potential Climate Changes, Impacts on Marine Transportation, and Adaptation Options -- Annex 5-1C: Potential Climate Changes, Impacts on Air Transportation, and Adaptation Options -- Summing Up -- Which Climate Changes Are Most Relevant for U.S. Transportation? -- How Will Climate Change Affect U.S. Transportation? -- How Should Transportation Decision Makers Respond? -- What Data and Decision Support Tools Are Needed? -- Which Adaptation Strategies Make Sense? -- What Actions and Research Are Needed to Prepare for Climate Change? -- Appendices -- A Detailed Statement of Task -- B Contribution of U.S. Transportation Sector to Greenhouse Gas Emissions and Assessment of Mitigation Strategies -- C Commissioned Papers and Authors -- D Conference Agenda and Participants. Every mode of transportation in the United States will be affected as the climate changes. Potentially the greatest impact on transportation systems will be the flooding of roads, railways, transit systems, and airport runways in coastal areas because of rising sea levels and surges brought on by more intense storms. Although the impacts of climate change will vary by region, they will be widespread and costly in human and economic terms and will require significant changes in the planning, design, construction, operation, and maintenance of transportation systems. This National Research Council report presents an overview of the scientific consensus about the current and future climate changes affecting U.S. transportation, including the limits of scientific understanding of the timing, magnitude, and location of the effects; identifies the potential impacts on U.S. transportation and the options for adaptation; and recommends research and actions to prepare for climate change. The report also summarizes previous work on strategies for reducing the transportation-related emissions of carbon dioxide - the primary greenhouse gas - which contribute to climate change. -- from back cover.