A Weakened AMOC = A Colder Northern Europe

It looks like my winter exercise program will continue to consist of moving increasing amounts of fresh snow. Skiing to the local store in Mosvik (7 km) or Straumen (13 km) is another option.

The reason for this prediction is that the Gulf Stream aka Atlantic Meridional Overturning Circulation (AMOC), carries warm water north-eastwards towards Europe and beyond. In the arctic it cools, becomes denser and sinks, and then flows back southwards, along the Atlantic coast of North America. Now, global warming is reducing the cooling effect, while melting Greenland ice is diluting and weakening the current.

New research (see sources below) shows the current is now 15% weaker than around 400AD, with human-caused global warming being a major contributor to this. Human-caused global warming? That is a polite term for the burning of fossil-fuels, which increases the amount of CO2 in the atmosphere. The consequences of more CO2 could be disastrous.  During the last ice age, changes in AMOC led to 5-10C winter temperature reductions in as short a time as one to three years. This had major consequences then and could have major consequences now.

Recent (black) and maximum (grey) glaciation of the northern hemisphere during the Quaternary climatic cycles. (Illustration: Hannes Grobes, 2008)


Popular: https://www.theguardian.com/environment/2018/apr/11/critical-gulf-stream-current-weakest-for-1600-years-research-finds

Scientific: https://www.nature.com/articles/s41586-018-0007-4 and https://www.nature.com/articles/s41586-018-0006-5