Climate change is often associated with increasing global temperatures but ironic as it may seem, a phenomenon caused by global warming appears to also increase the odds of colder winters in Eurasia.
Findings of a new research conducted by climate scientists from Japan suggest that the melting of the Arctic sea ice, which is attributed to the warming climate, can have an impact on the global circulation of air current which could lead to colder winters in Europe and Asia.
In the new study, which was published in journal Nature Geoscience on Oct. 26, Masato Mori, from the Atmosphere and Ocean Research Institute of the University of Tokyo in Japan, and colleagues looked at the possible association between the decline of the Arctic sea ice and the extreme weather in the Northern Hemisphere.
By running computer model simulations to determine what happens given actual sea ice measurements that were made since 2004, the researchers found that the melting of the sea ice in Barents and Kara Seas has doubled the odds of snowier and colder winters in Eurasia since 2004. The Barents-Kara Sea, located off the east-northeast of Norway and Russia, has significantly declined over the past 30 years.
"We use a 100-member ensemble of simulations with an atmospheric general circulation model driven by observation-based sea-ice concentration anomalies to show that as a result of sea-ice reduction in the Barents-Kara Sea, the probability of severe winters has more than doubled in central Eurasia," the researchers wrote. "Sea-ice decline leads to more frequent Eurasian blocking situations, which in turn favour cold-air advection to Eurasia and hence severe winters."
Colin Summerhayes, from the Scott Polar Research Institute in the UK, said that the counterintuitive effect of climate change that caused the decline of sea ice could get people into thinking that global warming has ended but it has not. The Arctic is in fact warming fast.
Experts have also warned for a long time that global warming does not just involve the gradual increase in global temperatures. The phenomenon is also believed to be driving more frequent occurrence of extreme weather events.
"Annual average global temperatures continue to rise, but the distribution of temperature through the year is giving us more extremes," University of Cambridge professor Peter Wadhams said. "As ice continues to retreat, we can expect these weather extremes to continue to occur and maybe worsen."
