According to a new study published Monday in the journal Nature Climate Change the global sea levels are rising at a faster rate than it was previously proved by other studies. It seems that over the past 15 years the rate at which the sea level has rose has accelerated.
The research team formed of international scientists has analyzed satellite records made from 1993 to mid-2014 and compared them to tide gauge records. According to the UN’s (IPCC) Intergovernmental Panel on Climate Change of the year 2013 the global sea level rose by 19 centimeters between 1901 and 2010, which means an average of 1.3 millimeters (0.06 inches) per year. IPPC’s Fifth Assessment Report said that between 1993 and 2010 the average rate rose to 3.2 millimeters per year.
So previous research based only on satellite or tide gauge lone suggested that the rising of sea level has slowed down. A study conducted in 2014 claimed that over the past 10 years compared to the previous decade.
The lead author of the study, geophysicist Christopher Watson of the University of Tasmania, said that the study from 2014 was confusing since it coincided with a period of time when West Antarctica and Greenland had increasing water. This gave scientists some hope making them believe that the rising sea levels might not be an inexorable threat, but they may fluctuate according to an unknown natural variability.
However this new study proves the contrary. The researchers analyzed both satellite data which shows changes in sea levels and fine shifts in land formation and records of tidal gauges around the world which contained data from a period of ten years. The study corrected errors which have been in the satellite record of sea levels for a long time. Such an example is the global mean rate of sea level which has indeed risen between 1993 and mid-2014, but only between 2.6 and 2.9 millimeters per year. The previous study overestimated the sea level rise, distorting the bigger picture and preventing scientists from noticing the tendency of the accelerating sea level rise.
Watson remarked that given the fact that water is exchanged between land and sea the levels of the sea can naturally fluctuate. That is why the higher rate of increase suggested by the study is too small to be considered statistically significant. He explained that what is certain is the fact that sea levels are rising at nearly the double of the average rate observed in the last century and this has severe implication for the coastal cities around the world.
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