Stark warning 'cold blob' could cause 'very serious problems' for Scotland's climate

A world-leading oceanographer has warned a fragile Atlantic climate system at risk of reaching a tipping point in the next 25 years could cause “many very serious problems” for Scotland.

Scientists have raised concerns that the Atlantic Meridional Overturning Circulation (AMOC) is at risk of reaching a tipping point by the middle of this century that could see it collapse - with dire consequences for Scotland’s climate.

Scotland could suffer an annual mean temperature change of up to -2.4°C in ‘an idealised future CO2 doubling scenario in which the AMOC has fully collapsed’.

The AMOC keeps Scotland much warmer than other locations on the same latitude such as Labrador in Canada which sees winter temperatures plummet to -15C in the winter.

It works by bringing warm water north and cold water south like a central heating system - but a ‘cold blob’ in the North Atlantic is being caused by a significant slowdown in the Gulf Stream due to global warming as the AMOC weakens.

Read more: Why Scotland is one of the most sensitive places in the world to climate change

The so-called “cold blob” sits between Greenland, Iceland, Ireland and Scotland and is thought to be the only place on earth that is cooling amid global warming.

Professor Stefan Rahmstorf, who addressed the Nordic Circle Assembly on his fears in October, has warned the cold blob “has been cooling over the past decades”.

The expert has stressed that if the system does collapse it would lead to “a really shocking cooling in the Nordic seas” of around 20C in annual mean temperatures.

He added that if you look at all modelling, “you can also see the entire Northern Hemisphere cooled and the entire Southern Hemisphere warmed”, with IPCC forecasting for 2100 showing “the cold blob actually expands in these scenarios”.

Scotland could suffer from more extreme temperatures when the AMOC collapses (Credit: Getty Images) | Getty Images

Professor Rahmstorf said this would mean “cooling down Ireland and Scotland”.

He has warned: "For some countries that will be in the midst of this, like Norway and Scotland, the risks will be existential and raise the question whether people can continue to live there or whether most of them would rather move."

The latest IPCC report found that even if emissions are reduced, the AMOC will weaken between 4 per cent and 46 per cent by the year 2100.

But worryingly, Professor Rahmstorf said “the climate models are under-estimating this problem”.

Meltwater from the Greenland ice sheet is slowing down the Atlantic Ocean current that includes the Gulf Stream (Picture: Kerem Yucel/AFP via Getty Images)

He added that the AMOC has a “tipping point”, warning that “if you add some freshwater”, like occurs when the Greenland ice sheet melts in the North Atlantic at an accelerated rate due to the climate crisis, “the AMOC gets weaker”.

Professor Rahmstorf has suggested that the tipping point for the AMOC is “probably in the first half of this century”.

He added: “This risk is much greater than we thought just five years ago.”

He said that “once the AMOC has collapsed in a globally-warm world” contrasts between a larger cold blog and areas of heat “drive storms” and “drive extreme events”.

Professor Rahmstorf added: “If you have southern Europe warming and northern Europe cooling, that’s really bad news for extreme events.

Read more: The four biggest SNP climate failures campaigners want rectified in 2025

“There are big sea level changes in response to an AMOC collapse. There are many very serious problems.”

Lang Banks, director of WWF Scotland, said: “Scotland’s already feeling the effects of our changing climate – sadly we’ve all witnessed the flooding of farmland, towns and cities.

“These are all stark reminders that the climate crisis is not going away. Storms that were once described as ‘once in a decade’ are now happening far more regularly.

“We urgently need a repeat of the success we’ve already seen on renewables, in sectors such as agriculture, home heating, and transport.

“We therefore need the Scottish and UK governments, politicians from all parties, businesses, and the public to all play their part in delivering a climate and nature-friendly future.”