Forecast Changes in Sea Levels. Melting of the Greenland Ice Sheet

Forecast Changes in Sea Levels. Melting of the Greenland Ice Sheet

Posted on 10 Jan 2018

Part of the Greenland ice sheet.  Global composite coverage obtained between 08.01.2017 and 11.30.2017 using data from the MODIS spectroradiometer aboard KA Terra.
http://owm.io/sql-viewer?lat=62.6060&lon=-42.0364&zoom=10&where=between(2017-08-01:2017-11-30)&select=red,green,blue&op=rgb&from=cloudless&tabActive=1

Most forecasts say that warming of our planet will continue and is likely to accelerate. Recent research shows that the oceans will rise from 2.5 to 6.5 feet (from 0.8 to 2 meters) by 2100, enough to submerge many cities on the US Eastern Seaboard. But long-term forecasts are not an exact science.
Historically there have been problems matching the changes observed with factors from different sources that supposedly contribute to this process.
At the moment, it has been established that changes in global sea levels are affected by three factors: melting of the polar ice caps and glaciers, thermal expansion of water due to warming of the seas and oceans, and local factors such as changes in marine currents and geological processes (land rising and subsidence) which overlap with the global trend.
Both with the polar icecaps and with the glaciers, the rise in air temperature causes increased melting of large ice cover.
For example, should the Greenland ice sheet alone melt, the sea level could rise by 7m.

Global coverage obtained between 08.01.2017 and 11.30.2017 using data from the MODIS spectroradiometer aboard KA Terra.
http://owm.io/sql-viewer?lat=72.1009&lon=-43.7695&zoom=4&where=between(2017-08-01:2017-11-30)&select=b1,b4,b3&op=rgb&from=terra&tabActive=1

However, rising in sea levels around the world will not be uniform.
Even melting of different parts of the same ice sheet can have radically different consequences for different parts of the world. For example, if the western part of the Greenland ice sheet melts, the consequences will make themselves felt in London.

Global coverage obtained between 08.01.2017 and 11.30.2017 using data from the MODIS spectroradiometer aboard KA Terra.
http://owm.io/sql-viewer?lat=65.4651&lon=-51.3611&zoom=7&where=between(2017-08-01:2017-11-30)&select=b1,b4,b3&op=rgb&from=terra&tabActive=1

But, if the north-eastern side melts instead, then it is bad news for New York.

Global coverage obtained between 08.01.2017 and 11.30.2017 using data from the MODIS spectroradiometer aboard KA Terra. 
http://owm.io/sql-viewer?lat=74.5433&lon=-23.0273&zoom=6&where=between(2017-08-01:2017-11-30)&select=b1,b4,b3&op=rgb&from=terra&tabActive=1

In the opinion of researchers, melting in the southern hemisphere of part of the Antarctic icecap could spell great danger to the inhabitants of Sidney, Australia.
However, despite this frightening scenario, existing models that show melting of the polar icecap are unable to duplicate the collapse of the ice cover which occurred 14,000 years ago when sea levels rose at an average speed of one meter every 20 years over 400 years. As was the case when the Earth was 3 ° C warmer, during the Mid-Pliocene age around 3 million years ago, and sea levels were approximately 25 meters (80 feet) higher than today. 

Therefore, at present, the rapid melting of Greenland which without a doubt will have a great influence in the future, is not impossible but is considered unlikely,which allows it to be omitted as a factor in future forecasts for rising sea levels.
Thermal expansion of water happens when the upper waters of seas and oceans heat up due to a rise in the air temperature. In the future, warming of the oceans, which will take more and more of a hold on the planet, will make a substantial contribution to rising sea levels. But at this time, while this factor can lead to dangerous consequences in the future, so far it is not playing a decisive part.
In such a way, while this is still weak as a global trend, local processes can play a decisive part in the distribution of global sea levels. For example, at the moment, despite the global rise in sea levels, there are still areas where sea levels are subsiding, for example in the Indian Ocean and the Maldives.