But in Siberia, it wasn’t just May that was warmer than usual — the region experienced periods of higher-than-average surface air temperatures throughout winter and spring, with warmer temperatures particularly from January, C3S found.
“It is undoubtedly an alarming sign,” said Freja Vamborg, a senior C3S scientist.
Siberia tends to see large temperature variations month-to-month and year-on-year, and there have been months in previous years when the temperature anomalies were larger than what the region has experienced in the past six months, C3S said. But, according to C3S, it’s unusual to see warmer-than-average temperatures for so many months in a row.
Although the Earth as a whole is warming, temperature rises don’t occur evenly across the planet, Vamborg said.
She said western Siberia stands out as a region that shows more of a warming trend with higher variations in temperature.
Effects of warmer temperatures
The warmer temperatures already appear to be having negative impacts.
Nornickel, the energy company’s parent, said the foundation of the storage tank possibly sank due to thawing permafrost, highlighting the dangers increasingly warming temperatures pose to Arctic infrastructure and ecosystems, according to Russian state news agency TASS.
“Right now we can assume … that due to abnormally mild summer temperatures recorded in the past years, permafrost could have melted and the pillars under the platform could have sank,” said Nornickel chief operating officer Sergey Dyachenko, according to TASS.
Sergey Verkhovets, coordinator of Arctic projects for Russia’s WWF branch, said that the incident led to catastrophic consequences.
“We will be seeing the repercussions for years to come,” Verkhovets said. “We are talking about dead fish, polluted plumage of birds, and poisoned animals.”
CNN’s Mary Ilyushina and Frederik Pleitgen contributed to this story.