GR: Coastal flooding as global warming melts the polar ice caps is one of the most devastating consequences of human-caused climate change. Years ago, scientists predicted that at some point, the rate of sea level rise would accelerate. We have now passed that point. According to NOAA, “nuisance flooding” is already becoming a problem on the U. S. east coast where high tides will be higher than many other places on the globe. Here’s a story on what scientists expect. You will notice that global annual averages are small. However, when you consider totals for decades, and when you consider that the totals will be much higher in some areas like the U. S. east coast, you can see how great the threat is.
“A new scientific analysis finds that the Earth’s oceans are rising nearly three times as rapidly as they were throughout most of the 20th century, one of the strongest indications yet that a much feared trend of not just sea level rise, but its acceleration, is now underway.
“We have a much stronger acceleration in sea level rise than formerly thought,” said Sönke Dangendorf, a researcher with the University of Siegen in Germany who led the study along with scientists at institutions in Spain, France, Norway and the Netherlands.
“Their paper, just out in the Proceedings of the National Academy of Sciences, isn’t the first to find that the rate of rising seas is itself increasing — but it finds a bigger rate of increase than in past studies. The new paper concludes that before 1990, oceans were rising at about 1.1 millimeters per year, or just 0.43 inches per decade. From 1993 through 2012, though, it finds that they rose at 3.1 millimeters per year, or 1.22 inches per decade.
“The cause, said Dangendorf, is that sea level rise throughout much of the 20th century was driven by the melting of land-based glaciers and the expansion of seawater as it warms, but sea level rise in the 21st century has now, on top of that, added in major contributions from the ice sheets of Greenland and Antarctica.
“The sea level rise is now three times as fast as before 1990,” Dangendorf said.
–Chris Mooney, More: New study finds the oceans are rising three times faster than they were during the 20th century – The Washington Post