Coastal Impacts, Adaptation, and Vulnerabilities - Climate ...

Physical Climate Forces 51niche erosion/block collapse are expected. Thaw slumping will also accelerate due towarming of the atmosphere (factor 3), but this process would not be directly changed byoceanic changes.A final Arctic coastal process that appears to be affected by climate change is themigration of barrier islands in the Alaska Beaufort Sea in the Arctic Ocean. In the past,these barrier islands have been observed to migrate westward due to the predominanteastern winds and waves. Ravens and Lee (2007) provide evidence that the western endof one of these islands, Narwhal Island, is migrating at an accelerating rate. Accordingto GIS analysis and GPS surveys, between 1955 and 1990, the western end of the islandmoved at about 5 meters/year. However, in the last two decades between 1990 and 2007,it has moved at 25 meters/year on average.The recently published IPCC Special Report on Managing the Risks of ExtremeEvents and Disasters to Advance Climate Change Adaptation “Report for Policy Makers”(IPCC, 2012) indicates that temperature increases and increased variability, includinggreater potential for extremes, will continue to be strong for coastal regions. ThisIPCC result is based on an average of results from a series of climate projection modelsoperated by different research groups and represents the benchmark for assessing whatis likely to occur with continued climate warming.