Climate Science

Greenland"The utterly plausible case that climate change makes London much colder" - Financial Times 11 January 2025

The FT's article is a climate landmark: one of the rare times a serious, widely-read and respected newspaper has highlighted the very serious risks and consequences of climate change.  This time, a slowdown of the Atlantic Meridional Overturning Current (AMOC).  The slowdown and/or its consequences has been documented by many climate scientists, including James Hanson and Stefan Rahmstorf (see his talk about tipping points in another blog entry) since the 1990s.  A slowdown and eventual halting of AMOC is expected to eventually result in a reduction of average temperatures in northern Europe (including the UK) of as much as 10 degrees Celsius.  This may not sound much, but it will have major consequences, especially for food production as balmy southern England will turn into an artic circle-like climate and agriculture as we know it (and many other things) will cease, with major consequences for northern Europe's food security.  Think The Day after Tomorrow movie minus the high drama.

AMOC transports warm, salty water from the southern oceans up to to the Arctic, cooling West Africa and eastern South America and warming the ocean west of the UK and Europe, up to Greenland.  When the water cools down, the density increases, making it sink down and return to the southern ocean, where it warms again.  Increasing ocean temperatures and other factors, including melting of Greenland's ice sheet (Arctic ice cover is pretty much shrinking every year) which dilutes the ocean's saltiness, are causing the motor which drives AMOC to slow and likely eventually to stop.  So the warm water will no longer moderate northern Europe's climate.  Once the current slows down and stops it will not restart - a tipping point.  The question of course is the rate of slowdown.  But, given the consequences, we cannot afford to be complacent and action of cutting greenhouse gas emissions is needed now.

​The link to the original article is here.






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