This story was originally published by Grist and is reproduced here as part of the Climate Desk collaboration.

For years, scientists have been keeping a wary eye on the massive system of currents that carry water and nutrients across the ocean from Greenland to Antarctica. The Atlantic Meridional Overturning Circulation plays a large part in stabilizing the global climate, but it appears to have been weakening in recent years as the Earth warms. Should it collapse, drought would spread across the Southern Hemisphere and the Eastern Seaboard of the United States would see catastrophic sea level rise. It could also trigger a series of other tipping points, from which the Earth would likely not recover.

“We are basically moving faster into high risk territory now.”

To avoid this scenario, 195 countries signed onto the Paris Agreement in 2015—a landmark treaty that aimed to keep global warming below 1.5 degrees Celsius over pre-industrial times. Beyond that threshold, scientists say, the Earth’s climate could begin to deteriorate in unpredictable and irreversible ways. The past few years have been the warmest on record, and the importance of staying within this limit has been driven home as deadly heatwaves and rampant wildfires have become routine.

A recent study published in Geophysical Research Letters claims that warming has........

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