Greenhouse effect

Nearly impossible without man-made global warming, this year's freak Siberian heat wave is producing climate change's most flagrant footprint of extreme weather.

A study found that the greenhouse effect multiplied the chance of the region's prolonged heat by at least 600 times, and maybe tens of thousands of times.

Case of Siberia

In the study, the team looked at Siberia from January to June, including a day that hit 100 degrees (38 degrees Celsius) for a new Arctic record.

Scientists from the United Kingdom, Russia, France, Netherlands, Germany and Switzerland used 70 climate models running thousands of complex simulations comparing current conditions to a world without man-made warming from the burning of coal, oil and gas.

They found that without climate change the type of prolonged heat that hit Siberia would happen once in 80,000 years, “effectively impossible without human influence,” said study lead author Andrew Ciavarella, a scientist at the UK Met Office.

Comparative analysis over six months

The team looked at both the average temperature in Siberia over the first six months of the year when temperatures averaged 9 degrees (5 degrees Celsius) above normal and the heat spike of 100 degrees occurred in the Russian town of Verkhoyansk in June. Both just really couldn't happen in a world without the additional heat-trapping gases from burning fossil fuel, Ciavarella said.

Thawing permafrost a trigger

The scientists said the heat added to problems with widespread wildfires fires, pest outbreaks and the thawing of permafrost which led to a massive pipeline oil spill.

Thawing permafrost also has the potential to release huge amounts of greenhouse gases trapped under the frozen ground, which could then worsen the warming, scientists said.

Connecting the dots

These types of studies allow people and world leaders to “connect the dots” between extreme weather events and climate change and prepare for them, said French climate scientist Valerie Masson-Delmotte, who wasn't part of the research.

“The climate of the future is very different as this paper shows,” said Pennsylvania State University meteorology professor David Titley, who wasn't part of the research. “We can either adapt or suffer."

Not peer-reviewed yet plausible

But the researchers who specialise in these real-time studies usually do get their work later published in a peer-reviewed journal and use methods that outside scientists say are standard and proven.

2020's Siberian heat wave stood out among the many studied, said attribution team co-lead Friederike Otto, acting director of Oxford University's Environmental Change Institute.

https://economictimes.indiatimes.com/news/environment/global-warming/climate-change-makes-siberian-heat-600-times-likelier/not-peer-reviewed-yet-plausible/slideshow/76993829.cms


Source: 16 July, 2021, The Economic Times