Friday, January 16, 2009

US report on sea level rise paints an alarming picture

EPA: The U.S. Environmental Protection Agency, in collaboration with other agencies, has released a report that discusses the impacts of sea level rise on the coast, coastal communities, and the habitats and species that depend on them. The report, Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region, examines multiple opportunities for governments and coastal communities to plan for and adapt to rising sea levels.

Sea-level rise can affect coastal communities and habitats in a variety of different ways, including submerging low-lying lands, eroding beaches, converting wetlands to open water, intensifying coastal flooding, and increasing the salinity of estuaries and freshwater aquifers. It is caused by a number of natural and human-induced factors and can vary by region. Some impacts of sea-level rise can already be observed along the U.S. coast. Among the report highlights:
  • Rising water levels are already an important factor in submerging low-lying lands, eroding beaches, converting wetlands to open water, and exacerbating coastal flooding. All of these effects will be increased if the rate of sea-level rise accelerates in the future.
  • Most coastal wetlands in the mid-Atlantic would be lost if sea level rises one meter in the next century. Even a 50-cm rise would threaten most wetlands along the Eastern Shore of Chesapeake Bay.
  • Possible responses to sea level rise include seawalls, bulkheads, and other shoreline armoring; elevating buildings and land surfaces (including beaches and wetlands); and allowing shorelines to change and moving structures out of harm’s way. Those three approaches have very different environmental and social impacts.
  • Preparing now can reduce the eventual environmental and economic impacts of sea level rise.
  • Some governmental and nongovernmental organizations are already starting to prepare for sea level rise.

Sunset on a northern island beach (Ocracoke Island, Outer Banks, North Carolina, United States), shot by Vbofficial