Monday 6 September 2021

‘Colder winters caused by Arctic global warming’

Climate change in the United States has been caused by global warming in the Arctic.

That is the key finding from a new study published in the journal Science, which claims that Arctic change is a major causal factor for extreme cold weather witnessed in the US during the last 40 years.

The authors have linked what they call a ‘stratospheric polar vortex disruption’ (SPV), or the heating in the Arctic disturbing patterns of wind, to periods of extreme cold in the northern hemisphere.

Warming in the Arctic has been far more extreme than elsewhere on Earth and has led to a heavy loss of summer sea ice.

The researchers explain that the region is heating at a rate that is twice the global average and believe SPV is to blame for extreme cold in East Asia and North America - including the most recent Texas cold wave in February of this year.

According to the report, melting ice caps are leading to more snow in Siberia, which is impacting winds above the North Pole that stretch to the US and Asia through the vortex.

The authors used numerical modelling linked to weather trends to reach their conclusion and hope the findings will convince people that global warming is a complex issue and colder weather does not mean climate change is not occurring.

Lead author of the study, Dr Judah Cohen, said: "We're arguing that melting sea ice across Northwest Eurasia, coupled with increased snowfall across Siberia is leading to a strengthening of the temperature difference from west to east across the Eurasian continent.

"We know when that temperature difference increases, that leads to more disruptions of the polar vortex. And when it's weakened, that leads to more extreme winter weather such as the Texas cold wave last February."