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Researchers have found that the planet is moving toward climate conditions that have disrupted key Atlantic currents in the past.
Recently, more and more talk about climate crisis, which hung over the planet like a black cloud, raining waves of unbearable heat and drought on the Earth. But something similar has already happened to our planet, at least this is indicated by a new study, he writes Live Science.
During the last interglacial period, the global warming of the Earth led to the melting of an incredible amount of Arctic ice, which led to the collapse of the Atlantic currents. Scientists now believe that these are the same conditions we are moving towards.
Global warming led to the destruction of vital currents in the Atlantic Ocean just before the last ice age. In turn, the weakening of the currents caused a cascade of effects that led to a sharp cooling of the Greenland, Icelandic and Norwegian seas, while the surrounding oceans, on the contrary, became warmer. Now scientists believe that today we are moving in the same direction.
According to the lead author of the study, associate professor and paleoceanographer at the Arctic University of Norway Mohamed Ezat, the results are really alarming. The last interglacial period, between 130 and 000 years ago, was a relatively warm period in Earth's history. During this period, the world faced higher temperatures, higher sea levels, and smaller ice sheets. Climatologists believe that this interglacial period is probably an analogue of our climatic future.
During the study, the scientists found that about 128 years ago, the increased melting of the Arctic sea ice had a significant effect on the overturning circulation in the northern seas. The flow of these seas plays an important role in the Atlantic Meridional Overturning Circulation (AMOC), which includes the Gulf Stream.
Melting Arctic glaciers, as scientists know, can significantly affect the AMOC, as fresh water entering the North Atlantic dilutes surface waters, preventing them from sinking to the bottom and forming deep currents. Scientists also discovered that the main arteries of the ocean are slowing down significantly, and the reason for this is anthropogenic climate change. Forecasts also predict the collapse of the system in the coming decades.
Climate models suggest that the AMOC could collapse by 2100, but there are huge uncertainties in predicting the time frame. In the new study, Ezat and colleagues analyzed new and previously collected data from sediment cores from the Norwegian Sea. They compared this data with similar information from North Atlantic sediments to reconstruct the distribution of sea ice, sea surface temperature, salinity, deep ocean convection and sources of meltwater during the last interglacial period.
The results indicate that Arctic meltwater blocked the formation of deep-sea currents in the Norwegian Sea during the last interglacial period. This significantly slowed the southward movement of the AMOC, in turn slowing the engine that carries heat into the Northern Hemisphere. Now scientists believe that something similar is likely to await us in the future, and by the middle of the century we will be facing an ice-free summer.
