Estimated effects of climate change on flood vulnerability of U.S. bridges

We assessed the potential impacts of increased river flooding from climate change on bridges in the continental United States. Daily precipitation statistics from four climate models and three greenhouse gas (GHG) emissions scenarios (A2, A1B, and B1) were used to capture a range of potential changes in climate. Using changes in maximum daily precipitation, we estimated changes to the peak flow rates for the 100-year return period for 2,097 watersheds. These estimates were then combined with information from the National Bridge Inventory database to estimate changes to bridge scour vulnerability. The results indicate that there may be significant potential risks to bridges in the United States from increased precipitation intensities. Approximately 129,000 bridges were found to be currently deficient. Tens of thousands to more than 100,000 bridges could be vulnerable to increased river flows. Results by region vary considerably. In general, more bridges in eastern areas are vulnerable than those in western areas. The highest GHG emissions scenarios result in the largest number of bridges being at risk. The costs of adapting vulnerable bridges to avoid increased damage associated with climate change vary from approximately $140 to$250 billion through the 21st century. If these costs were spread out evenly over the century, the annual costs would be several billion dollars. The costs of protecting the bridges against climate change risks could be reduced by approximately 30% if existing deficient bridges are improved with riprap.United States. Environmental Protection Agency. Office of Atmospheric Programs (Contract #EP-W-07-072

Institutional Barriers to Climate Change Adaptation in U.S. National Parks and Forests

Climate change will increasingly challenge ecosystem managers' ability to protect species diversity and maintain ecosystem function. In response, the National Park Service and the United States Forest Service have promoted climate change adaptation as a management strategy to increase ecosystem resilience to changing climatic conditions. However, very few examples of completed adaptation plans or projects exist. Here, we examine managers' perceptions of internal and external institutional barriers to implementing adaptation strategies. We conducted semi-structured interviews (n=32) with regional managers and agency staff in six park and forest units in Washington State. We found that internal barriers, including unclear mandates from superiors and bureaucratic rules and procedures, are perceived as greater constraints than external barriers related to existing federal environmental laws. Respondents perceived process-oriented environmental laws, such as the National Environmental Policy Act, as enablers of adaptation strategies, and prescriptive laws, such as the Endangered Species Act, as barriers. Our results suggest that climate change adaptation is more often discussed than pursued, and that institutional barriers within agencies limit what can be accomplished

The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment

A report that provides a comprehensive, evidence-based estimation of observed and projected climate change related health impacts in the United States