2 yıl önce

US report predicts century's worth of sea rise in just 30 years

By 2050, seas lapping against the US shore will be 10 to 12 inches higher, a new government report warns.

AP

The projected increase is especially alarming given that in the 20th century, seas along the Atlantic coast rose at the fastest clip in 2,000 years.

America's coastline will see sea levels rise in the next 30 years by as much as they did in the entire 20th century, with major eastern cities hit regularly with costly floods even on sunny days, a government report has warned.

By 2050, seas lapping against the US shore will be 10 to 12 inches (0.25 to 0.3 metres) higher, with parts of Louisiana and Texas projected to see waters a foot and a half (0.45 metres) higher, according to a 111-page report issued on Tuesday by the National Oceanic and Atmospheric Administration and six other federal agencies.

"Make no mistake: Sea level rise is upon us," said Nicole LeBoeuf, director of NOAA's National Ocean Service.

The projected increase is especially alarming given that in the 20th century, seas along the Atlantic coast rose at the fastest clip in 2,000 years.

LeBoeuf warned that the cost will be high, pointing out that much of the American economy and 40 percent of the population are along the coast.

However, the worst of the long-term sea-level rise from the melting of ice sheets in Antarctica and Greenland probably won’t kick in until after 2100, said ocean service oceanographer William Sweet, the report's lead author.

Warmer water expands, and the melting ice sheets and glaciers add more water to the world's oceans.

New level of flooding

The report "is the equivalent of NOAA sending a red flag up" about accelerating the rise in sea levels, said University of Wisconsin-Madison geoscientist Andrea Dutton, a specialist in sea level rise who wasn't part of the federal report.

The coastal flooding the US is seeing now "will get taken to a whole new level in just a couple of decades."

"We can see this freight train coming from more than a mile away," Dutton said in an email. "The question is whether we continue to let houses slide into the ocean."

Sea level rises more in some places than others because of sinking land, currents and water from ice melt.

The US will get slightly more sea level rise than the global average. And the greatest rise in the US will be on the Gulf and East Coasts, while the West Coast and Hawaii will be hit less than average, oceanographer Sweet said.

SOURCE: AP