It Happened 8 Thousand Years Ago...

About 8 thousand years ago things got a lot cooler - 3.3°C cooler. It got cooler because the surface waters of the North Atlantic became fresher - and less heavy.

Because they are less dense they cannot sink. If they don't sink warmer waters cannot come northwards to replace them. And so northern Europe suffers from a cold Atlantic and temperatures drop. And you get a drought. The technical term for this is "a perturbation of the Atlantic Meridional Overturning Circulation (AMOC)".

The cause, 8 thousand years ago, is thought to be the draining of Lake Agassiz in central Canada. Measurements made in the Ythan estuary just north of Aberdeen show sea level rising 2.4 m at 13mm per year around 8.5 thousand years ago.

Worryingly, the same thing is happening now, but with a different cause. The Greenland is cap is melting. It rained on the top of the ice cap (3.2km in elevation) in 2021 for the first time ever!

At first sight the fall in temperature because of global warming might seem to be a good thing. But I doubt it. Adding chaos to chaos is seldom beneficial.

Read all about this in THIS ARTICLE.