Recall that earlier a group of researchers from Germany, Great Britain and Ireland gave a similar forecast in the journal Nature Geoscience. This is the so-called Atlantic meridional overturning circulation (AMOC). This is a whole system of currents of the Atlantic Ocean, which is sometimes even called the “kitchen” of the weather. One of the branches of AMOS is the famous Gulf Stream. The climate on the entire planet depends to a greater or lesser extent on it, but especially in the countries of North America and Europe, making it warmer and more temperate. After all, warm water masses warm the air above them, which is carried by the westerly winds to all of Europe, including, by the way, Russia. Due to such warming, air temperature deviations from average latitude values in January reach, for example, 15-20°C in Norway and more than 11°C in Murmansk.
Scientists have been talking about the fact that AMOS, and with it the Gulf Stream, have been slowing down for about 30 years. Why are they now not just stating a fact, but giving an SOS signal? The fact is that the currents began to decrease much more than before. Estimates show that due to anthropogenic influences alone, current intensity at the beginning of the 21st century decreased by 5-10% compared to the mid-19th century. And then – more. If global warming is not stopped, by the end of this century the intensity of the Gulf Stream will decrease by 20-30%.
How critical is this for the climate? Are Europe and North America, which could lose their ocean warmer, in danger of a new “glacier”? Not everything is so clear here.
The fact is that the Gulf Stream is a single current. It circles Florida, flows along the east coast of the United States, then breaks off the coast and heads northeast. Similar exist in the Pacific Ocean – Kuroshio, and in the Southern Hemisphere. But only the Gulf Stream, after breaking away from the American coast, does not return to the subtropics, but partially penetrates to the north, towards high latitudes. This is why in the North Atlantic the temperature is 5 to 10 degrees higher than in similar latitudes in the Pacific Ocean or in the Southern Hemisphere.
This unusual “trick” of the Gulf Stream has a reason. The highly salty water from the tropics, brought by him to the North Atlantic, cools there and therefore tends to sink to the bottom. And as they say, a sacred place is never empty: instead of water that has sunk to the depths of the North Atlantic, water comes from the south, providing a favorable climate in Europe and North America. Why is the Gulf Stream slowing down now? Blame it all on global warming. “The fact is that the huge land glaciers, mainly the Greenland glacier, are melting, desalinating surface waters and preventing them from sinking, thus interrupting the work of the ocean conveyor that has been established for thousands of years to supply warm water to the North. Atlantic,” says academician Vladimir Klimenko.
Could the Gulf Stream ever stop? What, by the way, do not exclude some climate scenarios? And won’t many of the currently fertile regions of the northern hemisphere turn into deserts? According to academician Klimenko, this is an incredible scenario. To do this, the increase in the average temperature of the planet at the end of the century should not reach 2 degrees, provided for by the Paris climate agreement, but many times more. For such an option, no apocalyptic image will seem redundant. It will be about the existence of humanity.
About 8,200 years ago, the Gulf Stream had already stopped, but the northern territories did not turn into a frozen desert.
But still, if you imagine how unbelievably the Gulf Stream stops, will North America and Europe freeze? Will vast regions turn into a frozen desert? It turns out that in its history, nature has periodically carried out such experiments.
– About 8.2 thousand years ago there was a grandiose climatic catastrophe: the ice barrier of the Laurentian ice sheet collapsed, which blocked the entire sea of melt water, located on the site of the present Hudson Bay in America North, – says Klimenko. – A giant mass of meltwater for about two decades ended up in the North Atlantic, sharply desalinating it. The ocean conveyor stopped, the average temperature in the Northern Hemisphere dropped, but not tens of degrees, but probably one or two, and in some places up to five. The northern territories did not turn into a frozen desert, and most importantly, after 200 years the ocean conveyor was completely restored.
The warm current of the Gulf Stream moves from Florida to the Scandinavian Peninsula, Svalbard, the Barents Sea, and the Arctic Ocean. Photo: NOAA
In a word, the scenarios that scare some scientists are probably the next climate “horror stories.” If the average temperature in the countries of North America and Europe, including Russia, can drop, then this will not seriously affect the weather. Also, under current conditions, the slowdown in the Gulf Stream could be a boon for humanity. In any case, for residents of a number of regions of the Northern Hemisphere. After all, when global warming is rapidly approaching Earthlings, the slowdown in the Gulf Stream reduces its “rise” to the overall temperature.
– Yes, there is such an effect, but it is not about Europe, but about parts of Greenland and Baffin Island, – says academician Klimenko. – This is the only area on the planet where in the last 100 years it has not become warmer, but colder. And precisely because of the slowdown of the Gulf Stream. In Europe, the impact of this phenomenon is very small.
The Gulf Stream is a system of warm currents in the North Atlantic Ocean from Florida to the Scandinavian Peninsula, Svalbard, the Barents Sea, and the Arctic Ocean. The temperature at the water surface is +25…+26 C, at a depth of 400 m – +10…+12 C. The length of the current to Svalbard is about 10 thousand km.
The width of the Gulf Stream is 70-90 km, the maximum speed is several meters per second in the upper layer of the ocean, which decreases with depth (up to 10-20 cm/s at depths of 1000-1500 m). .
Thanks to the Gulf Stream, the countries of Europe adjacent to the Atlantic Ocean have a milder climate than other regions at the same geographical latitude: masses of warm water heat the air above them, which is carried to Europe by westerly winds.