Identifying climate and other scenarios that influence the performance of coastal infrastructure projects in Alaska

Climate change influences sea levels, ocean acidification, extreme weather, ecosystem balance, and other phenomena of importance to natural and man-made systems, as well as long-term national security issues. Climate and other uncertainties should be addressed through scenario analysis when considering societal issues and response policies and investments. The consequences and risks of climate change and sea-level rise are increased by ongoing development and the aging of coastal infrastructure protection. The US Army Corps of Engineers (USACE) is concerned with incorporating the direct and indirect physical effects of projected changes of climate to the management, planning, engineering, designing, construction, operation, and maintenance of USACE projects that mitigate coastal erosion. Multiple rates and events of climate change address uncertainty in the evaluation of project alternatives. Evaluating and designing alternatives over the full spectrum of sea-level rise rates and other scenarios increases the chance of selecting the appropriate projects for success. Such analyses must consider the issues of human health and safety, economic costs and benefits, aging infrastructure systems, environmental and ecological aspects, and other social effects. Our effort is developing a methodology for identifying the most influential scenarios for infrastructure policies and investments for protection from coastal erosion. The methodology quantifies the sensitivity of twenty-six Alaska infrastructure projects to a variety of scenarios. For each scenario, the methodology elicits from experts the increases or decreases in importance of criteria to rank project needs.