A new study has revealed that the Atlantic Ocean circulation or the Atlantic overturning has become the weakest in the last 1600 years. The study says the climate change is the main reason behind the slowing down of Atlantic overturning. As per the study, the Atlantic Ocean circulation has declined in strength by 15 percent since the mid-20th century to a “new record low and this has happened due to the changing climate. This indicates about the growing impact of climate change on the oceans of the world.
Atlantic overturning involves warmer water flowing from equator towards the high altitude of the Atlantic and the cold water from there flowing down towards the equator through the deep ocean. The Atlantic Meridional Overturning Circulation (AMOC) is also called the current of the Gulf Stream. So, if the AMOC weakens, the strength of the current of the Gulf Stream weakens. Scientists have said that if global warming intensifies then it will collapse the Gulf Stream and hence all of Western Europe will face extreme winter and the eastern seaboard of the U.S. will see a rise in the sea level with tropical rainfall.
Normally what happens is that the Atlantic Ocean circulation takes the warmer waters from the equator towards the North Pole and there the water cools and comes down as cold water towards the equator. But the current global warming has disturbed the Atlantic overturning hence there is accumulation of more warm waters at the North Atlantic thus leading to melting of glaciers in Arctic Lead author of the study, Levke Caesar from the Potsdam Institute for Climate Impact Research (PIK) said that their team discovered a specific pattern of ocean cooling at the south of Greenland and unusual warming off the US coast, which were indications of the weakening of the AMOC.
Co-Author David Thornalley of the University College London said, “AMOC is a really important part of the Earth’s climate system and it has played an important part in abrupt climate change in the past.” The researchers of the latest study say that at present no climatic model gives a precise prediction about whether the AMOC shutdown will occur or not. But given that the changes in climate had previously resulted in 5-10 degree of temperature rise in the last ice age, there is an urgent need to check global warming to avoid the Gulf Stream collapse.