The rise in sea level is one of the most worrying effects of global warming. Millions of people live on the shores and on low-lying islands, so if action is not taken, there will undoubtedly be massive migrations within a few decades.
Until now it was thought that the average level of the oceans increased at a rate of 1,3-2mm per year; However, new research has shown that it rises faster.
During the last century the information scientists obtained about sea level rise came from a network of tide gauges that are located along the coasts. These instruments are very useful if you want to know how much has increased in these areas, but they will not give you an overall result as they will be determined, as explained by the lead author of the study Sönke Dangendorf, by the vertical earth movement of the earth's crust and by the regional variability patterns that result from changes in ocean circulation, wind redistribution or the effects gravitational effects of the redistribution of masses of water and ice on Earth.
Now scientists have altimeters that, on board satellites, monitor sea levels in all oceans.
So, to find out exactly how fast sea level has risen since the XNUMXth century, what they did was select the longest and highest quality records, and correct all those factors that could give an erroneous result and then take a global average. In this way, they were able to discover that until before 1990 the sea level had risen 1,1mm per year, but since the 1970s it has risen considerably due to the impact of humans on the environment.
With the rise in the global average temperature, the melting of the poles makes the coasts less and less unprotected.
You can read the full study here.