Collapse of Atlantic Currents Could Drive a Surge in Warming
A vast system of Atlantic currents appears to be weakening, and scientists say its collapse could lead to dramatic cooling in northern Europe. A new study suggests an additional risk: a surge in warming across the rest of the globe. Read more on E360 →
Scientists warn that a weakening Atlantic current could trigger a sharp rise in global warming. The Atlantic Meridional Overturning Circulation, or AMOC, transports warm water from the tropics to Europe. As it flows north, this water cools, becomes denser, and sinks, then returns south. However, as oceans heat up, the water is less cool and dense, leading the AMOC to weaken.
This slowdown is exacerbated by the Greenland ice sheet melting, releasing fresh water into the North Atlantic, which is less dense than salty water and slows the circulation. If the AMOC were to collapse, northern Europe could see temperatures drop by 9 to 27 degrees Fahrenheit (5 to 15 degrees Celsius), according to one estimate.
While the weakening of the AMOC is not new, a recent modeling study shows a more alarming scenario. In the past, when the North Atlantic cooled, southern regions warmed by an equal amount, keeping the overall heat constant. However, this new study reveals a more drastic outcome: during previous AMOC weakenings, the Earth became significantly hotter overall.
Lead author Christo Buizert of Oregon State University explains that the AMOC acts like a heat valve, regulating the planet's energy budget. When the AMOC is strong, warm water flows to the North Atlantic, where the heat is released into the atmosphere. Conversely, when the AMOC is weak, heat accumulates in the ocean.
Buizert suggests that past weak periods of the AMOC resulted in warming equivalent to 10 years of current human-driven emissions. Although studies of past AMOC shifts may not perfectly match today's changes, they offer valuable insights for understanding potential future impacts as global temperatures continue to rise.
Written by urgent.news from Yale Environment 360's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
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