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Unprecedented heat in Siberia pushed planet to warmest June on record, tied with last year

Triple-digit heat infiltrated the Arctic Circle

An analysis of land surface temperature anomalies during June. (Copernicus/ECMWF)

June 2020 tied for the planet’s warmest on record, closely matching the anomalously toasty temperatures observed globally during June last year. But one region in particular saw heat virtually off the charts — Siberia.

Uncharacteristically warm weather and at least one instance of triple-digit heat thawed vast stretches the Arctic, contributing to a flare-up in wildfires and melting away permafrost in a process set to accelerate the pace of human-induced climate change.

It was Siberia’s hottest June on record, beating out the previous record holders — 2018 and 2019 — by a significant margin, according to the Copernicus Climate Change Service, a science division of the European Union.

Rapid Arctic meltdown in Siberia alarms scientists

Across the entirety of Arctic Siberia, June temperatures averaged about nine degrees above normal. A few places bordering the Laptev Sea in northeast Siberia spent the month 18 degrees above normal. An anomaly like that would be the equivalent of New York City averaging a high of 104 and low of 87 degrees every day during the month of July.

Triple-digit heat even occurred in Siberia during June, the town of Verkhoyansk cresting at 100.4 degrees on the afternoon of June 20. The World Meteorological Organization has preliminarily accepted the reading as legitimate, marking the hottest temperature ever observed in the Arctic.

Signs of the Arctic warming at breakneck pace

Climate scientists have long concerned themselves with Siberia and the Arctic, zones which are outpacing almost everywhere else in the world when it comes to climate warming by a factor of almost three. The heating in this region unlocks several large-scale feedback mechanisms that quicken the rate of climate warming even further.

Among those byproducts of the red-hot Arctic have been melting snow and ice in recent years, leaving more of the adjacent Arctic Ocean ice-free during part of the year. Current Arctic sea ice extent was at record-low levels for July, a roughly a million-square-mile deficit in areal ice coverage when compared to average levels in the 1980s. That’s an area about 3½ times the size of Texas.

Cutting back on the amount of ice in the Arctic means there’s less to reflect sunlight, allowing the surface to absorb more of the sun’s rays and heat up disproportionately faster than the rest of the world.

That’s also triggering the same positive feedback mechanism on land, by melting Siberia’s snowpack and even thawing its previously untouched permafrost.

An eroded snowpack and parched soil catapult ongoing warming

Scientists with the climate monitoring service Copernicus reported a record minimum in snowpack across Siberia during June, catapulting the region’s ability to heat up. The severely reduced snow cover also left surface moisture exposed and able to freely evaporate, resulting in record dry soils. That fosters even greater warming, since dry air can heat up more quickly than moist air.

That was reflected in a spate of extreme heat that brought temperatures exceeding 90 degrees to Verkhoyansk — about 70 miles north of the Arctic Circle — for nine days within a 10-day stretch between June 19 and June 28. Verkhoyansk is about 1,300 miles farther north than Fairbanks, Alaska. For comparison, Buffalo has never hit 100 degrees in its 147 years of records.

Wildfires rage across Siberia

The prolonged hot, dry conditions have also jump-started Siberia’s summer wildfire season at an alarming clip. Scientists at Copernicus said that last summer’s Siberian wildfires were the most widespread since at least 2003 and evolving in similar way to last year, which was a record-setter.

“Higher temperatures and drier surface conditions are providing ideal conditions for these fires to burn and to persist for so long over such a large area,” Copernicus senior scientist Mark Parrington said in a news release.

‘Zombie fires’ are erupting in Alaska and likely Siberia, signaling severe Arctic fire season may lie ahead

Wildfire emissions further intensify climate change

Wildfires are both a product and a catalyst of climate change. They feed off the progressively hotter and drier weather that’s infiltrating the Arctic, while their combustion releases droves of greenhouse gases into the atmosphere by the ton.

Blazes in the Arctic pumped some 59 megatons of carbon dioxide into the atmosphere during the month of June alone, the worst wildfire emissions in the Copernicus data set.

All that CO2 enters the atmosphere, where it can drive accelerated warming.

A similar melting of Arctic permafrost is having an equally disconcerting effect, releasing previously trapped greenhouse gases back into the atmosphere.

The Arctic may have crossed key threshold, emitting billions of tons of carbon into the air, in a long-dreaded climate feedback

Warmth all around the globe

The anomalous heat in Siberia extended into Northern Europe, where impressive warmth also hovered over Scandinavia. Helsinki, the capital of Finland, has seen its warmest year to date by a wide margin, while Stockholm experienced its warmest June on record. France has also seen its warmest year to date on record, a feat shared by southeast Norway. Europe as a whole concluded its second warmest June on record.

It comes as the entire planet wrapped up its warmest June on record, tied with last June. Temperatures globally averaged out to 0.95 degrees (0.53 Celsius) above the 1980-to-2010 mean. This follows the warmest May on record.

In addition, the Copernicus data shows the planet’s average temperature over the last 12 months was on par with the warmest one-year period on record, 2.3 degrees (1.3 Celsius) above preindustrial levels.

This puts the planet perilously close to one of the temperature guardrails outlined in the Paris climate agreement, in which policymakers agreed to limit global warming to “well below” 3.6 degrees Fahrenheit, or 2 degrees Celsius, above preindustrial levels by 2100. The aspirational goal in the agreement is to hold temperatures to a 2.7-degree increase, or 1.5 Celsius, above preindustrial levels, which is a target that was pushed by the countries considered most vulnerable to climate impacts, such as small island nations.

2°C: Beyond the Limit

Jason Samenow and Andrew Freedman contributed to this report.