The melted Greenland ice sheet makes sea level rise faster

A research team led by geologist Anders Carlson of the University of Wisconsin - Madison reported that sea levels rise because the greenhouse effect affects the Greenland ice sheet to double or even triple the current estimate. in the next century.

Carkson, a professor of geology and geophysics at the University of Wisconsin - Madison, said: 'Let's talk about disaster. We can see a much larger answer than the current estimate when it comes to rising sea levels due to the Greenland icebreaker disintegrating in the next 100 years. " Carlson collaborates with a group of national researchers. They include Allegra LeGrande of NASA Climate System Center at Columbia University and colleagues at Woods Hole Oceanographic Institute, California Institute of Technology, British Columbia University and New Hampshire University.

At this time scientists had to agree on the extent to which the sea level of Greenland ice sheet melted. This land strip spreads about 1.7 million square kilometers. According to Carlson, in the historical record there has been no precedent about the impact of climate change on a giant ribbon.

'We have never seen a strip of tape disappear before, but we have a record.' The new study uses a combination of modern computer models with land and ocean records to get accurate information about the melting rate of ice sheets as well as the speed of sea level rise when the world Warm up day by day.

When the Greenland ice sheet melts, the sea level will rise and increase rapidly. (Photo: NASA / Jesse Allen and Robert Simmon)

Carlson and his team were able to learn the lesson of the disappearance of the Laurentide ice sheet - the last ice sheet to cover much of the northern hemisphere. The Laurentide ribbon, which previously covered much of the current territory of Canada and the United States, began to melt about 10,000 years ago under the influence of increased solar radiation in the northern hemisphere, the main cause being cyclic transformation in the orientation of the Earth axis.It experienced two rapid-melting waves, one that occurred 9,000 years ago and another about 7,600 years ago, causing global sea levels to rise by more than 0.5 inches annually.

According to new research, two melting waves occur when summer temperatures are at the same level as predicted in Greenland by the end of the century. The findings suggest that estimates of sea level rise due to global warming are severely low.

The latest prediction of the sea level rise caused by the Greenland ice sheet has been provided by the Intergovernmental Panel on Climate Change (IPCC), the Intergovernmental Panel on Climate Change (IPCC). 100 years to about 1 to 4 inches. According to Carlson and his colleagues, this estimate is based only on limited data, mainly from the past decade and the opposition is telling the results of future climate computer models. This raises doubts about the current estimate of sea level change due to melting ice.

According to new research, sea water will increase from 1/3 inch per year to about 1 to 2 futures within a century . Although the global sea level has risen slightly, it is also a big problem because there are many people in the world, with hundreds of millions of people, living in vulnerable areas due to rising sea levels.

Carlson said: 'We think IPCC schemes are conservative. That's an underestimated estimate of the extent to which the Greenland ice sheet affects the sea level . ' The authors of the New Geoscience report also cite the contraction of the Laurentide ice sheet as well as its impact on sea level by determining the time when the rock was exposed to cosmic radioactive exposure. , estimates of the shrinkage of the ice sheet are calculated based on the date of radioactive carbon from organic materials as well as the changes in seawater salinity.

Other co-authors involved in external research Carlson and LeGrande also have Gavin A. Schmidt of Columbia University, Delia W. Oppo of Woods Hole Oceanographic Institution, Rosemarie E. Came of California Institute of Technology, Faron S. Anslow. of the University of British Columbia, Joseph M. Licciardi of New Hampshire University and Elizabeth A. Obbink of the University of Wisconsin-Madison.

Refer:
Anders Carlson et al.Rapid early Holocene deglaciation of the Laurentide ice sheet.Nature Geoscience, August 31, 2008