Could the UK actually get colder with global warming?

Of all the possible climate futures, there’s a scenario where the United Kingdom and north-west Europe buck the trend of global warming and instead face plunging temperatures and freezing winters.

It’s not the most likely outcome, but a number of scientists fear that the chance of it happening is growing, and that the consequences would be so great that it deserves proper consideration.

They are concerned that the ocean currents that bring warm water from the tropics to the North Atlantic could weaken – or even collapse – in response to climate change.

Huge uncertainties remain about when – or even whether – a collapse could happen. So, how likely is it, and what would it mean?

The system of Atlantic currents, called the Atlantic Meridional Overturning Circulation (Amoc), is a key reason why the UK is warmer than Moscow, despite being a similar distance from the Equator.

Forming a vital part of our climate system, this conveyor belt distributes energy around the planet, bringing warm, salty water from the tropical Atlantic to cooler regions south of Greenland and Iceland, and also the Nordic Seas.

The warmth from the ocean is transferred to the air above it, helping keep temperatures milder than they otherwise would be.

As this salty water cools, it becomes denser, and sinks, before flowing back towards the southern hemisphere as a deep ocean current. This water eventually gets pulled back up to the surface, and the circulation continues.