Siberia's lengthy heatwave impossible without climate change, scientists say

The lengthy heatwave hitting Siberia that saw a record-breaking high of 100.4 degrees last month would not have happened without climate change, according to an international team of scientists.

The vast Russian province has been baking since January with temperatures more than 9 degrees above average for the first six months of the year, according to the World Meteorological Organization. The hot conditions sparked wildfires that burned more than 2.8 million acres in late June.

An analysis led by the U.K.'s Met office and published Wednesday, found that the prolonged heatwave was made 600 times more likely because of human-caused climate change.

"This study shows again just how much of a game changer climate change is with respect to heatwaves," Friederike Otto, one of the study's co-authors, said in a statement on Thursday.

The World Meteorological Organization said the findings were among the strongest results of studies to date attributing the effects of human-induced climate change on extreme weather events.

The drawn-out hot spell is a very rare event, expected to only occur once every 130 years, even with climate change, the study found. But had it happened in 1900, the heatwave would have been 3.6 degrees cooler than the temperatures seen this year.

By 2050, a similar hot spell could be as much as another 9 degrees warmer than what has been seen now, the report said.

Such high temperatures in the Arctic circle come with many consequences for the environment and communities.

The widespread fires that began in June released about 56 million tonnes of carbon dioxide — a figure that is more than the annual emissions for many countries such as Switzerland and Norway, the World Meteorological Organization said.


Students of the Optimist children's sailing school take part in a training session in the Irkutsk, Russia, water reservoir.Alexei Kushnirenko / TASS/Getty Images


The combination of emissions from the fires and melting of permafrost in the Arctic circle due to the heat will only exacerbate global warming, the organization said.

The heatwave in Siberia has also contributed to making the global average temperature for first five months of 2020 the second-hottest on record, the study found.

Heatwaves are also among the deadliest extreme weather events, according to the World Health Organization. A 44-day extreme heat event in Russia in 2010 resulted in 56,000 deaths.

Given the risks to human health, measures need to be taken to mitigate the effects of heatwaves, even in historically cold climates, said Otto, the acting director of the Environmental Change Institute at the U.K.'s University of Oxford.

"As emissions continue to rise we need to think about building resilience to extreme heat all over the world, even in Arctic communities — which would have seemed nonsensical not very long ago," she added.

The findings also have scientists urging for a reduction in global greenhouse gas emissions.

"We are starting to experience extreme events which would have almost no chance of happening without (a) human footprint on the climate system," said Sonia Seneviratne, a climate scientist with the Institute for Atmospheric and Climate Science of the ETH Zurich.

"We have little time left to stabilize global warming at levels at which climate change would remain within the bounds of the Paris Agreement," she added referring to the 2015 accord which saw 195 countries set their own national targets for reducing or controlling pollution of heat-trapping gases.

President Donald Trump withdrew the U.S., the second-biggest climate polluter and world's largest economy, from the Paris Agreementin May 2017 and kick-started the process last November.

However, the withdrawal process takes a year and wouldn't become official until at least the day after the 2020 presidential election.