'We are approaching the tipping point': Marker for
the collapse of key Atlantic current discovered
Scientists have discovered a key warning sign before a
crucial Atlantic current collapses and plunges the Northern Hemisphere into
climate chaos.
The Atlantic Meridional Overturning Circulation (AMOC)
carries warm water north from the Southern Hemisphere, where it releases heat
and freezes. The freezing process concentrates salt in the non-frozen portion
of the ocean water; this extra-saline water sinks, travels back south and picks
up heat again, restarting the conveyor belt. (The Gulf Stream is part of this
belt.)
This release of heat helps keep Europe, and to some
extent North America, balmier than it otherwise would be. But sediment records
over the past 100,000 years suggest that, at times, the AMOC has shut down
abruptly, leading to major climate shifts over mere decades.
Scientists believe we could be veering towards this
scenario once again — potentially as early as 2025 — as a result of climate
change. However, until now researchers had no way of telling if the current is
on the path toward one of these tipping points.