Global sea levels could rise two or even three times higher over the next century than the UN previously estimated, according to a study by the U.S. National Research Council.
The Tehran Times reports that a committee of experts has taken previous UN data and evaluated it against new data the council collected, updating projections with new data on the polar ice caps melting, believing that this is one reason the sea level is rising more rapidly than expected.
As a result, the NRC estimates that global sea levels will rise between 22 and 55 inches by the year 2100. The Tehran Times reports that Robert Dalrymple, committee chair and professor of civil engineering at Johns Hopkins University stated:
“Our answers are pretty much in line with what others have done except that the IPCC was a little timid in 2007 about the ice contribution, so using more current information about the ice melt we have a bigger contribution there.”
France 24 reports that researchers are using a wide range within each estimate, because of increasing uncertainty about sea level projections, because they do not have all of the data they need to assess what could happen further into the future. They do predict in the near future that there will be a global sea level rise of three to nine inches by 2030, and seven to 19 inches by the year 2050.
According to France 24, the committee came together because of an executive order from California, who requested a sea level rise assessment in order to inform preparations for coastal impact, and also to have detailed predictions for the U.S. West Coast. The NRC found that the sea level will most likely rise faster than global estimates in southern California, because of land erosion and subsiding coastline.
The northern part of the state, as well as the coasts of Oregon and Washington will most likely see less of an impact than the rest of the world, because, the report states that:
“The lower sea levels projected for northern California, Washington and Oregon coasts are because the land is rising largely due to plate tectonics. In this region, the ocean plate is descending below the continental plate at the Cascadia Subduction Zone, pushing up the coast.”