A “collapse” of key Atlantic ocean currents system would cause winter temperatures to plunge across northern Europe, overriding the global warming due to human activity, according to new research published in Geophysical Research Letters, which takes into account the combined impact of the shutdown of the Atlantic Meridional Overturning Circulation (AMOC) and global warming on temperatures in northern Europe.
According to studies published in the journal Nature, “Atlantic Meridional Overturning Circulation” (AMOC) is in a weaker state now than it has been for decades – and possibly even centuries.
Carbon Brief stated that in an intermediate emissions scenario, greenhouse gas-driven warming would not be able to outweigh the cooling impact of an AMOC collapse.
As per the estimates mentioned by Carbon Brief, one-in-ten winters in London could experience cold extremes reaching -20 degrees Celsius. Winter extremes in Oslo in Norway, are expected to plummet to around -48 degrees Celsius.
Claiming that Europe might stand alone as the one region set to get “cooler in a warmer world”, Lead author Dr René van Westen, a researcher in oceanography at Utrecht University, told Carbon Brief, “If the AMOC collapses, we need to prepare for substantially cooler winters. Winter extremes will be very substantial for some regions. Temperatures could go down to -50C in Scandinavia. At -40C and lower in Scandinavia – everything breaks down over there.”
Presently, London experiences average winter temperatures falling to 1.9 degrees Celsius, with cold extremes reaching -19.3 degrees Celsius once every decade, reported Down To Earth. In Edinburgh, one-in-ten-year lows have reached -29.7 degrees Celsius, while Oslo sees average winter temperatures of -16.5 degrees Celsius. In modelled scenarios of an AMOC collapse, winter sea ice could extend to the coasts of Great Britain and Scandinavia, further amplifying regional cooling.
According to Down To Earth the research also underscored potential changes due to shutdown of the AMOC in the Intertropical Convergence Zone southwards, weakening monsoon systems across India, West Africa and the Amazon and altering rainfall patterns in the tropics.
The research showcased the risk that Europe could become an outlier in the climate crisis, cooling in winter even as the planet heated overall.
Why the AMOC Could Collapse
According to MIT, the AMOC could collapse as global warming is heating ocean waters and melting ice, increasing the volume of freshwater to the North Atlantic. This decreases salinity and density, making it difficult for water to sink and circulate. Without this sinking, the current grows weak or stops — disturbing the global climate and causing extreme regional changes.
