Read at www.theguardian.com
The circulation of the Atlantic Ocean, known as the Atlantic meridional overturning circulation (Amoc), is in danger of reaching a tipping point with dire consequences for the climate system and humanity, according to a new study. The researchers developed an early warning indicator based on computer models and past data, and found that Amoc is already on track towards an abrupt shift. The breakdown of Amoc, which is caused by the faster-than-expected melting of Greenland's glaciers and Arctic ice sheets, would disrupt global climate regulation and have far-reaching consequences for large parts of the world.
Using computer models and past data, the researchers developed an early warning indicator for the breakdown of the Atlantic meridional overturning circulation (Amoc), a vast system of ocean currents that is a key component in global climate regulation.
Amoc is currently in its weakest state in over a millennium, with a 15% decline since 1950. The melt-off of Greenland's glaciers and Arctic ice sheets is pouring freshwater into the sea, obstructing the sinking of saltier, warmer water from the south. This disrupts the circulation of heat, carbon, and nutrients, which are crucial for distributing energy around the Earth and moderating the impact of human-caused global heating. The new study has highlighted the urgency of addressing climate change and the need for immediate action to mitigate the effects of the melting ice and prevent an irreversible collapse of the Amoc.
The scientists behind the research said they were shocked at the forecast speed of collapse once the point is reached, although they said it was not yet possible to predict how soon that would happen.