WITH Scotland dipping to its coldest temper-atures for 35 years, and minus 21.9°C recorded in Braemar in Aberdeenshire in midweek, global warming may have been furthest from people’s minds.

But while former US president Donald Trump and climate deniers may point to colder winters as evidence that climate change is not at play, the fact that Scots are shivering under Arctic conditions this February can actually be attributed to global warming.

As we truly are experiencing Arctic conditions.

The polar vortex that sits high above the Arctic in the stratosphere is believed to have fed this cold snap which has had us thumbing through spells of weather. During the winter, a jet stream of air that keeps the polar vortex in place sometimes weakens, allowing its chilly air to extend southward.

Global warming is leading to less Arctic sea-ice cover, meaning there is more moisture from the sea migrating inland over normally dry Siberia.

This moisture then turns into snow, which reflects heat back into space and is making Siberia colder than norma,l which in turn disrupts a thermal band in the troposphere extending over Eurasia … and to us.

Judah Cohen, director of seasonal forecasting at Atmospheric and Environmental Research in Massachusetts, part of Verisk Analytics, a risk-assessment company, said: “Think of the polar vortex like a quiet, fast-spinning top that spins in place. Then, you have this energy [from the troposphere] that starts banging.”

For the Met Office it has been a very different landscape from last year when this month was the wettest the UK had experienced since 1862. That deluge was blamed on storms Ciara, Dennis and Jorge, sweeping in from the Atlantic which brought a large proportion of the month’s total rainfall on moisture-laden and relatively warm winds.

While the white-out in Scotland is another unwanted visitor from the east, Storm Darcy, and even colder than the Beast from the East in 2018.

Dr Mark McCarthy, head of the National Climate Information Centre, said: “The records from last week help to put the UK’s climate into context. For example, for all its roar, temperatures of below minus 20°C weren’t recorded during the Beast from the East during the end of February and the beginning of March 2018.

“But that event was certainly extreme by other measures, including widespread low daytime temperatures.

“Before last week we’d have to go back to December 2010 to see days where the UK temperature falls

below minus 20.0°C. In that year eight days saw temperatures below that value.”

Will this mean that we can expect more regular frozen winters? Since 1990, four years have recorded days below minus 20°C, but in the 30-year period up to 1990, 14 years reached that level.

McCarthy added: “Temperatures of this level have always been extreme events in the UK, but what our records show is that these events have become less frequent.

“However, the UK’s climate record displays a huge range of natural variation and even though our climate has warmed by approximately 1°C, there is still the possibility of a severe cold-weather event: they’re just not as regular as they used to be.”

Weather-watchers insist that we should not become complacent about the dangers of climate change.

McCarthy added: “January 2021 has been dominated by colder-than-average weather with only brief milder interludes, but what does this cold winter mean in the context of climate change and a warming planet?

“Well, a winter month as cold or colder than January 2021 used to occur in approximately seven out of 10 winters through the 20th century.

“In more recent decades this has dropped to around three in 10. So although we are still subject to cold weather in winter, these cold spells tend not to be as severe or as frequent as in the past.”

The British Antarctic Survey (BAS) is also keen to impress that climate change affects the full range of weather.

ANNA Jones, BAS’s interim director of science, said: “The term global warming is not very helpful in this discussion because it’s not just about warming, it’s about change.

“Within the context of climate change extreme weather change is going to become more common.

“The atmosphere is quite complicated and changes in one place can feed into another in quite surprising ways so that it is all very interconnected.

“It’s all nicely in balance but the more you change places where it’s warm and it’s cool then that’s what results in these extreme weather events.”

The director stresses that only the reduction in emissions will reverse this pattern.

She added: “Year on year, on year our measurements from the Antarctic are showing the concentration of greenhouse gases are going up.

“There is a very long ice core which has records going back 800,000 years and we have more carbon dioxide in the atmosphere than there has been in the previous 800,000 years. We’ve got about 30% more.”

For those in Braemar it might not feel like it but it would have been even cooler years ago.

Professor of climate system science at the University of Edinburgh School of GeoSciences, Gabi Hegerl, said: “We live with the fact that we get these outbreaks.

“We might get a bit more. But what is crystal clear is that it would have been a little bit colder in the 1950s for example.

We shouldn’t get relaxed about climate change though because of this, we just have to wait for the summer to see that, and we see the very dramatic heatwaves that we get.”