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

Vulnerability and Impacts on Human Development 85drilling facilities.The influence of rising temperatures on the rate of sea-ice decline and the thawing ofpermafrost in the Arctic coastal zone are likely to result in a number of impacts on theenergy sector, including:• Longer ice-free season for OCS exploration and production activities;• Opening up of navigation routes through the Northwest and NortheastPassages, even if ice simply thins to the point that shipping lanes can bemechanically maintained by icebreakers (Valsson et al., 2011);• Decline in the availability of ice-based transportation such as ice roads andoffshore loading facilities;• Frost heave and settlement of pipelines set on pilings or buried in permafrost;• Settlement of buildings set on piles or foundations laid directly upon permafrostor a decrease in load-bearing capacity of such structures;• Rapid, widespread environmental impacts could have substantial effects on theregulatory environment for OCS energy development (Ahmad et al., 2009);• Damage to onshore support facilities, waste-disposal sites, and roads as coastalerosion and land loss accelerates (Mars & Houseknect, 2007; Prowse et al.,2009); and• Hazards associated with the formation of thermokarst lakes in the coastal zoneand the stability of shelf and slope sediments due to thawing ice in sedimentsand the release of gas from clathrates (Figure 4-2).Alternate waste-disposal practices in the Arctic, including down-hole injection ortransportation of waste to more stable environments, are among the adaptations thatcould offset impacts and allow continued energy-resource development (Burkett, 2011).Several other adaptation strategies to the impacts of temperature change on Arctic explorationhave been proposed; for example, recent exploratory drilling in the BeaufortSea suggests that decreasing sea-ice cover may require design changes to counter effectsof increased wave action and storm surges. The use of barges for production, rather thana land-based facility, has been proposed for the Canadian coast (Prowse et al., 2009).Domestic offshore and inshore oil and gas facilities are vulnerable to accelerated sealevelrise due largely to the fact that the more than 4000 platforms and onshore supportfacilities that have been installed on the OCS in the Gulf of Mexico and along the westerncoast of the U.S. were not generally designed to accommodate a permanent increasein mean sea level or an increase in storm intensity. Relative sea-level rise (see Chapter 2),poses the greatest danger to the dense network of OCS marine and coastal facilities inthe central Gulf Coast region between Mobile Bay, AL and Galveston, TX. These facilitiesinclude ports, marinas, and OCS industry-support facilities such as tank batteriesand gas-processing plants. An increase in relative sea level of 61 centimeters has the potentialto affect 64 percent of the region’s port facilities; a 122 centimeter rise in relativesea level would affect nearly three-quarters of port facilities (CCSP, 2008).Hurricanes have been shown to have substantial and costly impacts on offshoreplatforms in the Gulf of Mexico. Storm surge effects include flooding and structural