In a new study, scientists found that human-caused climate change has disrupted a large system of Atlantic ocean currents, including the Gulf Stream.
The Atlantic Meridional Overturning Circulation (AMOC) is crucial to the world's oceans' functioning, transporting warm, denser saltwater from the tropics to northern Europe, where it cools and returns along the ocean floor.
Global weather patterns will be severely affected if it collapses.
This system is becoming increasingly vulnerable to disturbances, according to a new study published in the journal Nature Climate Change by the Potsdam Institute for Climate Impact Research in Germany.
The findings support prior studies that found the AMOC system to be at its most vulnerable in 1,600 years.
If this circulation fails, the Washington Post reports, it may bring extreme cold to Europe and parts of North America, as well as boost sea levels along the US coast. Seasonal monsoons, which provide water to much of the world, are disrupted along the East Coast.
According to The Guardian, it would also jeopardize the Amazon jungle and Antarctic ice sheets.
AMOC has been tied to a number of crises in the past. Another study released in February indicated that as Arctic ice and the Greenland Ice Sheet continue to melt, AMOC may drop by 34% to 45% by the end of the century.
The current paper, on the other hand, adds to the growing scientific worry over AMOC's integrity.
Due to the melting of a massive glacial lake, the AMOC was last altered roughly 12,000 years ago, near the end of the previous ice age. An extreme cold spell engulfed Europe for over a millennium.
AMOC has been thought to be decreasing for a long time as sea temperatures have risen due to human activities and greenhouse gas emissions. When greenhouse gases build up to the point where the AMOC will shut down is uncertain.
According to a 2016 study, if no substantial measures to reduce greenhouse gas emissions are done before then, the AMOC could collapse by 2300.
Due to the complexity of the AMOC system and uncertainties regarding future degrees of global warming, it is difficult to estimate the date of any collapse for the time being. It may take a decade or two, or it may take millennia.
However, scientists feel it should never be allowed to happen because of the serious consequences.
What we do know is that in the 540 million years since life became abundant on Earth, such upheavals have corresponded with a series of major extinctions.
