"The Gulf Stream system could collapse as soon as 2025, a new study suggests.
The shutting down of the vital ocean currents, called the Atlantic Meridional
Overturning Circulation (Amoc) by scientists, would bring catastrophic climate
Amoc was already known to be at its weakest in 1,600 years owing to global
heating and researchers spotted warning signs of a tipping point in 2021.
The new analysis estimates a timescale for the collapse of between 2025 and
2095, with a central estimate of 2050, if global carbon emissions are not
reduced. Evidence from past collapses indicates changes of temperature of 10C
in a few decades, although these occurred during ice ages.
Other scientists said the assumptions about how a tipping point would play out
and uncertainties in the underlying data are too large for a reliable estimate
of the timing of the tipping point. But all said the prospect of an Amoc
collapse was extremely concerning and should spur rapid cuts in carbon
Amoc carries warm ocean water northwards towards the pole where it cools and
sinks, driving the Atlantic’s currents. But an influx of fresh water from the
accelerating melting of Greenland’s ice cap and other sources is increasingly
smothering the currents.
A collapse of Amoc would have disastrous consequences around the world,
severely disrupting the rains that billions of people depend on for food in
India, South America and west Africa. It would increase storms and drop
temperatures in Europe, and lead to a rising sea level on the eastern coast of
North America. It would also further endanger the Amazon rainforest and
Antarctic ice sheets.
“I think we should be very worried,” said Prof Peter Ditlevsen, at the
University of Copenhagen in Denmark, and who led the new study. “This would be
a very, very large change. The Amoc has not been shut off for 12,000 years.”
The Amoc collapsed and restarted repeatedly in the cycle of ice ages that
occurred from 115,000 to 12,000 years ago. It is one of the climate tipping
points scientists are most concerned about as global temperatures continue to
*** Xanni ***
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