June 22 (Bloomberg) - Global warming may push sea levels as much as a foot higher in California in the next two decades, threatening airports, freeways, ports and houses, according to a report examining risks along the U.S. West Coast.
Increases are forecast to be greatest south of Cape Mendocino, with levels rising 12 inches (30 centimeters) by 2030 and as much as two feet by 2050, according to a report today by the National Research Council. In Oregon and Washington, increases may be more modest, because land also is rising. A major quake in the active seismic zone would change the forecast.
In addition, climate change may contribute to more frequent severe storms, the researchers concluded.
“As the average sea level rises, the number and duration of extreme storm surges and high waves are expected to escalate, and this increases the risk of flooding, coastal erosion and wetland loss,” Robert Dalrymple, chairman of the committee that wrote the report and a professor of civil engineering at Johns Hopkins University, said in a statement.
The report, which was requested by agencies in the Pacific Coast states, forecast that sea levels south of Cape Mendocino, which is about 270 miles (434 kilometers) north of San Francisco, might rise more than five feet (167 centimeters) by the end of the century, the panel said.
Rising sea levels along the California, Oregon and Washington coasts would confront commercial and residential developments that abut the Pacific Ocean, with airports, naval stations, freeways, stadiums and housing only a few feet above current high-tide levels, the authors said.
The National Research Council, a nonprofit organization based in Washington, provides scientific information for government decision-makers under the auspices of the National Academy of Sciences, the National Academy of Engineering and the Institute of Medicine. Panel members are volunteers, and their consensus reports undergo external peer review before completion.
The study was sponsored by federal agencies and the states.
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