Can Britain really get cold with global warming?

Among all possible climate futures, there is a landscape where the United Kingdom and the northwest Europe deer to the trend of global warming and faces temperature and cold winter instead.

This is not the most possible results, but many scientists fear that the possibility of this happening is increasing, and that the results will be so great that it is worthy of proper consideration.

They are worried that sea currents that bring warm water from tropics to North Atlantic, in response to climate change – may occur or even collapse.

The huge uncertainty remain about when – or even – a collapse can occur. So, how much it is, and what will it mean?

The system of Atlantic streams, called the Atlantic meridial overturning circulation (AMOC), is an important reason that the UK is warm compared to the UK Moscow despite the equal distance from the equator.

Creating an important part of our climate system, it distributes energy around the conveyor belt planet, which brings warm, salty water to cooler regions south of Greenland and Iceland from the tropical Atlantic, and also the Nordic sea.

The heat from the sea is transferred to the air above it, which helps to keep the temperature away.

As soon as this salty water cools down, it becomes dense, and drowns, before it flows back as a deep ocean towards the southern hemisphere. This water is eventually pulled back to the surface, and the circulation continues.

But Amoc is getting weaker.

We are certainly not knowing, because the direct and continuous measurement of Amoc strength has been taken only since 2004. This is not enough to be able to identify a certain change.

But indirect evidence suggests that it may already slow down about 15% in the last few centuries, although not all scientists agree.

An indication is sediment at the sea level. Large grains indicate a strong stream. By measuring the size of the grain and calculating their age, scientists can guess how slow the AMOC has over time.

Another piece of evidence is the so -called ‘Cold Blob’ or ‘Warming Hole’ in the North Atlantic. It describes an area that has cooled in recent decades contrary to the vast majority of the world.

A recession in the AMOC – which means low hot water will be taken to the region – is seen as a potential criminal.

It is the footprint of “a very clear signature and a classic AMOC recession” called Professor of Oceanography at Matthew England, South Wales University.

The United Nations inter -government panel on climate change (IPCC) hopes that Amoc will weaken the century. But the main concern is that Amoc may suddenly “switch off”, as it seems that the Earth’s past had repeatedly occurred.

Today, global warming is making water in the northern Atlantic low salty, a melting Greenland due to excess freshwater with snow sheet and excess rainfall.

Since fresh water does not drown easily, it is expected to slow down the circulation and so low saltwater is brought from the tropics to the north.

Beyond a “tipping point”, this loop can take the AMOC to the fugitive collapse.

David Thornley, Professor of Ocean and Climate Science at University College London, warned, “We really want to avoid a tipping point because then we cannot do anything about it.”

Nobody really knows how close it can be.

In 2021, IPCC stated that it was “moderate confidence” that Amoc would not suddenly fall in this century, although it was expected to weaken.

But some more recent studies have pointed to the growing possibility of passing a tipping point in the coming decades, with the complete collapse unavoidable.

Each study comes with different cavets and uncertainties, and different climate models can give different results to a system such as complex as AMOC.

Oceanographer of Met Office Dr. Laura Jackson said, “We are not confident that the idea of ​​an AMOC collapse in this century has largely changed due to these new results.”

But many scientists are becoming increasingly worried. Prof. Thorneley argues that, whatever individual studies have flaws, taken together, they “take to a conclusion that we probably need to be worried”.

Following new evidence, more than 40 major oceans and climate scientists signed An open letter Last October was called “much reduced by” for extensive recognition of risks.

This is not to say that signators believe that AMOC will pass a tipping point in this century. But they warns that it is now likely to consider properly.

“I would say that you are seeing the risk of reaching a tipping point in the coming decades, which can be at 10 or 20% level, even if we have 2C warming (above the temperature in the end of the 19th century, 19 At the end of the century, hold the line, humans began to heat the climate considerably), “Professor Tim Lenton of Earth System Science at Exeter University warned.

Given the horrors of the results from AMOC collapse, these possibilities are “trivial,” he says.

Even the most likely scenario – where AMOC weakens this century – can have a serious impact.

“If AMOC gradually becomes weak in the next century, you are going to get global warming but low warming on Europe,” Dr. Jackson says.

This would mean that Britain is getting hot summer with climate change, but a weak AMOC can also fuel more winter storms because regional temperatures change the pattern.

A full scale collapse, meanwhile, “will be like the war situation (…),” says Professor Lenton.

Although the effects may take a century or more time, the temperature in northern Europe may fall from one -two degrees in a decade.

In the UK, it can “badly, badly cool … such as living in Northern Norway,” Prof Thorneley warned.

“Our infrastructure is not established for.”

Global results can also be, such as changes in tropical rainfall belts.

“This is a big story,” warns Professor Lenton.

“If you lose the monsoon or obstruct it seriously, you will have human havoc, in simple terms, in West Africa (and) perhaps in India.”

How we prepare for this alternative future are challenges for governments.

Pro Lenton Kovid -19 draw similarities with the preparation of the epidemic – another major event that scientists warned, but there was no way to know when it could happen.

But Recently a report warned The Britain has “a national security blind place for climate threats” such as AMOC collapse. Government accepted last year It has not assessed the impact of any (AMOC) slow or collapse on the economic plan.

Scientists are clear that the fundamental way to reduce these risks is to cut greenhouse gas emissions, causing climate change.

“We’re playing a bit of a Russian Rule game,” pro England warned.

“The more we pile up the atmosphere with greenhouse gases, the more we heat the system, the greater the chance that we have an AMOC recession and collapse.

“And so I think people need not to give up, because a lot has to be achieved by reducing emissions.

“If we do nothing then the scale of change is very bad.”

Graphics by Erwan Revolt