The melting of glaciers could cause the circulation of the AMOC, a system of currents that bring heat to the northern hemisphere, to collapse in a few years, suggests recent research published in the journal Science Advances.
Without this additional heat source, average temperatures could drop several degrees in North America, parts of Asia and Europe, with dire consequences for much of the world, The Guardian reports.
Using computer models and previous data, a team of researchers at Utrecht University in the Netherlands developed an early warning indicator for a possible breakdown of the Atlantic Meridional Circulation (AMOC), a vast system of ocean currents which is a key component in global climate regulation.
The AMOC includes part of the Gulf Stream and other powerful currents, and is responsible for carrying heat, carbon and nutrients from the tropics to the Arctic Circle, where it cools and sinks into the deep ocean. This agitation helps distribute energy around the Earth and modulates the impact of human-caused global warming.
“We were surprised by the transient responses and climate impacts of the collapse of the Atlantic Ocean circulation,” explained the leader of the study, René van Westen, quoted in a university statement. According to his model, should the AMOC collapse, the European climate will cool by about 1°C per decade, but some regions would experience cooling of more than 3°C per decade.
Comparing these figures to the current global warming rate of 0.2°C per decade shows the unprecedented nature of the climate impacts that such a sharp drop in temperatures can bring.
“Colder temperatures in Europe may seem positive, but the repercussions are far-reaching: other regions are experiencing accelerated warming and altered precipitation patterns. In addition, a 100 cm rise in sea level is expected in Europe due to the abrupt collapse of ocean circulation,” Van Westen warned.
In addition to plunging several countries into a “deep freeze,” it would extend Arctic ice further south, further increase heat in the Southern Hemisphere, change global rainfall patterns and destroy the Amazon rainforest.
Until now there has been no consensus among scientists about the severity of the event and about the probability of its emergence in the 21st century. A study last year, based on changes in sea surface temperatures, suggested the tipping point could occur between 2025 and 2095.
However, the UK Met Office considers that large and rapid changes in the AMOC are “very unlikely” in the 21st century.
#Marine #currents #bring #heat #northern #hemisphere #collapse #glaciation #Diario #Página
