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In a new study, scientists focused on studying what would happen to the planet as a result of the collapse of one of the main "arteries" of the Earth.
Scientists are no longer afraid of the climate crisis, but directly declare that it is already here and affects all the most important systems of the Earth. As a result, the world has already faced incredible heat waves and droughts, and hurricanes and floods have become many times more extreme. In addition, for the past few years, scientists have been observing how the flow The Gulf Stream is slowing down, and fear that soon it may stop altogether, he writes Live Science.
If the currents of the Atlantic Ocean collapse due to the melting of the ice sheets, the researchers believe that there will be huge shifts in the tropical monsoon systems. In a new study, a team from the Technical University of Munich in Germany focused on studying what the consequences might be. The results of the new study suggest that the effects will be irreversible for at least the next 100 years.
Scientists have already found out that the Atlantic currents, which carry heat to the Northern Hemisphere, may stop due to climate change. Climate models suggest that if vital currents do weaken, tropical monsoon systems are likely to be thrown into chaos for at least a century.
Note that the Atlantic Meridional Overturning Circulation (AMOC) is a huge conveyor belt of ocean currents, including the Gulf Stream, which transports heat and salt from the South Atlantic to the North Atlantic. According to the study's lead author, Maia Ben-Yami, a climate researcher specializing in climate tipping points, the AMOC is essentially "Earth's giant fan." One of the reasons scientists are so concerned about the collapse of the AMOC is that it has a huge impact on the type of heat transport in the planetary system.
The team found that the Gulf Stream, which is part of the AMOC, is vulnerable to global warming as it causes the Earth's glaciers and ice sheets to melt. As a result of this process, a huge amount of fresh water is released into the North Atlantic, which dilutes the salinity of the upper layers of water and prevents them from sinking to the bottom of the ocean, where the circulation, as a rule, is directed back to the south.
According to Ben-Yami, the AMOC is actually mostly driven by saltier, denser water that descends to the north. The more fresh water gets here, the faster the circulation stops.
The researchers concluded that the collapse of the AMOC is likely to cause climate change worldwide, but will most affect the Northern Hemisphere and tropical monsoon regions. Note that scientists previously suspected that the collapse of the Gulf Stream and the AMOC in general would likely disrupt tropical monsoon systems. Now, the results of a new study describe in more detail how this will happen.
If the AMOC slows down or stops, it won't deliver the same amount of heat to the Northern Hemisphere, meaning sea temperatures there will be cooler. And if the Northern Hemisphere becomes colder, the hottest places on Earth will shift further south. As a result, the Intertropical Convergence Zone will move behind it, swinging up and down, but closer to the South Pole. As a result of such a shift, vital precipitation will also move.
During the study, Ben-Yami and colleagues used eight modern climate models, which allowed them to conduct a series of "pouring" experiments. The hose-down is equivalent to pouring fresh water into the North Atlantic to simulate the effects of melting ice. To reproduce the effects, the scientists did this over a simulated period of half a century until the AMOC eventually collapsed.
The results show that the collapse of the AMOC has led to disruption of tropical monsoon systems across the planet. As a result, the rainy season in West Africa, India and East Asia became much shorter and less intense. By the way, the current results also coincided with previous forecasts.
After the AMOC collapsed, the researchers turned off the "sprinkling simulation" and observed the system for the next 100 years. Despite the lack of fresh water, the tropical monsoons have not returned to their original state. As a result, scientists concluded that the effects of the collapse of the system are likely to persist for at least 100 years, and possibly longer.
