On Wednesday night the temperature in the Scottish village of Braemar dropped to -23C, making it the coldest night in the UK in 25 years, and the lowest February temperature since the 1950s.
While the Highlands are known for freezing winter temperatures, what has been dubbed “Beast from the East 2” has seen the mercury plummet across most of the UK, bringing widespread snow and ice.
For many people, chilly weather sits at odds with what we are told about climate change and our rapidly warming planet. How can the world be getting hotter when we’re so cold?
Try searching for “global warming” on Twitter or Facebook during a cold spell. You’ll see version after version of “I thought we had global warming”, usually in reply to a news report about the extreme weather, often accompanied by a variation on the side-eye emoji.
It’s difficult to tally pictures of metres-high snow drifts and weather maps covered in swathes of icy blue with the images we associate with global warming; firefighters tackling raging wildfires, cracked, drought-stricken river beds and packed beaches.
Researchers at the forefront of climate science are investigating the links between climate change and extreme weather events, such as severe cold spells.
Chloe Brimicombe, a PHD researcher specialising in extreme heat at the University of Reading, told HuffPost UK: “Global warming doesn’t mean we don’t get cold conditions.
“Climate overall is an average of weather conditions over time, and weather is not the same as climate. This is cold weather, which doesn’t mean that the climate isn’t warming.
“This cold weather event was linked to something called sudden stratospheric warming, and that can sometimes to lead to these cold weather events, which has been shown by some of my colleagues at the University of Reading, and that’s basically responsible for what has been called in the media ‘Beast from the East 2’.”
This area of research, Brimicombe explains, is highly debated – some scientists think that cold weather extremes could increase, or are already increasing with climate change due to the destabilisation of the atmosphere as a result of anthropogenic warming (warming driven by human activity).
The so-called Beast from the East is driven by stratospheric warming, that is, a warming in the part of the atmosphere above our own. When the stratosphere experiences warming, our part of the atmosphere – the troposphere – cools in order to balance the rising temperature.
Brimicombe said: “What we saw a couple of weeks ago in the Arctic was sudden stratospheric warming, which in turn caused something called a ‘blocking’, which is basically high pressure bringing the Beast from the East causing this cold weather.”
The last time Scotland saw temperatures comparable to Wednesday night was in 2010, during a similar period of freezing weather.
Brimicombe explained that while no two weather events are ever exactly the same, climate conditions were extremely similar during the two cold snaps due to the influence of La Niña, a huge ocean-atmosphere climate interaction which has a cooling effect in some parts of the world.
Its counterpart, El Niño, leads to warmer temperatures. According to a book published by the American Geophysical Union in late 2020, climate change could impact the frequency of extreme El Niño and La Niña events.
“Extreme El Niño and La Niña events may increase in frequency from about one every 20 years to one every 10 years by the end of the 21st century under aggressive greenhouse gas emission scenarios,” said Michael McPhaden, senior scientist with the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory. “The strongest events may also become even stronger than they are today.”
While the impact of climate change on cold weather continues to be investigated, we know that a warming planet is already contributing to more extreme weather – with heatwaves, droughts and storms intensified by rising global temperatures.