[D66] What a 100-degree day in Siberia really means

[R.O.]

  What a 100-degree day in Siberia really means

By
Alejandra Borunda
nationalgeographic.com
6 min
View Original 
<https://getpocket.com/redirect?url=https%3A%2F%2Fwww.nationalgeographic.com%2Fscience%2F2020%2F06%2Fwhat-100-degree-day-siberia-means-climate-change%2F>

An extended heat wave that has been baking the Russian Arctic for months 
drove the temperature in Verkhoyansk, Russia—north of the Arctic 
Circle—to 100.4°F on June 20, the official first day of summer in the 
Northern Hemisphere 
<https://www.nationalgeographic.com/science/space/what-is-summer-winter-solstice-answer-might-surprise-you/>. 
This record high temperature is a signal of a rapidly and continually 
warming planet, and a preview of how Arctic warming will continue in an 
increasingly hot future, scientists say.

“For a long time, we’ve been saying we’re going to get more extremes 
like strong heat waves,” says Ruth Mottram 
<http://research.dmi.dk/staff/all-staff/rum/>, a climate scientist at 
the Danish Meteorological Institute. “It’s a little like the projections 
are coming true, and sooner than we might have thought.”

Saturday’s record wasn’t just a quick spike before a return to more 
normal summer temperatures for the Russian Arctic: The heat wave behind 
it is projected to continue for at least another week. It was the 
hottest temperature ever recorded in the town 
<https://www.washingtonpost.com/weather/2020/06/21/arctic-temperature-record-siberia/>, 
where records have been kept since 1885.


    *A climate-toasted Arctic*

Hot summer days aren’t unheard of in the Arctic. The ocean-tempered 
coasts tend to stay slightly cooler, but inland, summer temperatures 
sometimes soar. Fort Yukon, Alaska, recorded the first-ever 100°F 
(37.7°C) day north of the Arctic Circle in 1915; Verkhoyansk hit 99.1°F 
(37.3°C) in 1988.

“At this time of the year, around the summer solstice, you get 24 hours 
of sunlight,” says Walt Meier 
<https://nsidc.org/research/bios/meier.html>, a climate scientist at the 
National Snow and Ice Data Center. “That’s a lot of solar energy coming 
in. So in these high-latitude areas—80 degrees, 90 degrees, that’s not 
unheard of.”

But climate change is “loading the dice” toward extreme temperatures 
like the one recorded this week, he says. The Arctic is warming more 
than twice as fast as the rest of the planet: Baseline warmth in the 
high Arctic has increased by between 3.6 to 5.4°F(2 to 3°C) over the 
past hundred or so years. About 0.75°C of that has occurred in the last 
decade alone 
<https://advances.sciencemag.org/content/5/12/eaaw9883?ftag=>. (Find out 
more about climate change and how humans are causing it 
<https://www.nationalgeographic.com/environment/global-warming/global-warming-overview/>.)

That means any heat waves that hit the region are strengthened by the 
extra warming. So the average warmness of a summer increases, and the 
extremes do too.

This month’s super-hot day emerged from a potent mix of factors. First, 
climate change nudged base temperatures up. Then, western Siberia 
experienced one of its hottest-ever spring seasons, according to climate 
scientists at the EU’s Copernicus Climate Change Service 
<https://climate.copernicus.eu/investigating-unusually-mild-winter-and-spring-siberia>. 
Since December, air temperatures in the region have averaged nearly 11°F 
(6°C) above the average seen between 1979 and 2019. The high heat is 
also likely well above the average seen in any similar six-month stretch 
going back to 1880. In May, air temperatures hovered some 18°F (10°C) 
above the “normal” May average of 33.8°F (1°C )—something that would be 
likely to occur only once in 100,000 years 
<https://twitter.com/MartinStendel/status/1270382142049091584>, if 
human-caused climate change 
<https://www.nationalgeographic.com/environment/global-warming/global-warming-effects/> 
hadn’t thrown a wrench in the climate system’s plumbing.

“It has been really bizarre to see,” says Ivana Cvijanovic 
<https://www.bsc.es/cvijanovic-ivana>, a climate scientist at the 
Barcelona Supercomputing Center. “All across Siberia, it has really been 
so hot for so long. January, then February, then March, then April. The 
pattern—it really stands out.”

The warm winter and hot spring meant that the snow usually blanketing 
the ground across much of the region melted about a month earlier than 
normal. Bright white snow plays a crucial role in keeping parts of the 
Arctic cool, by reflecting the sun’s incoming heat. Once it had gone 
away, dirt and plants readily soaked up the heat instead.

Then, the weather conditions aligned. A big, high-pressure system 
settled into place over western Siberia, where it stalled. These kinds 
of systems often have clear, cloudless skies—perfect for solar heat to 
shine through unobstructed, straight onto the hot Siberian ground.

“The air is just kind of trapped there; it’s like an oven sitting over 
the area, just heating it up more and more the longer it sits there,” 
says Meier.

In recent years, the effects of these kinds of immobile heat waves have 
become more obvious across the Arctic. In 2012, 97 percent of the 
Greenland ice sheet 
<http://nsidc.org/greenland-today/2013/02/greenland-melting-2012-in-review/>’s 
surface got so warm it turned essentially to slush. In 2016, it was so 
warm in High Arctic Svalbard, Norway, that rain fell instead of snow for 
part of the winter <http://nsidc.org/arcticseaicenews/2016/>. Last 
summer, the edges of the Greenland ice sheet experienced up to three 
extra months of melting weather 
<https://orbi.uliege.be/handle/2268/246645>. Limpid blue pools formed on 
its surface 
<https://www.nationalgeographic.com/environment/2019/09/greenland-ice-getting-denser-thats-bad/>; 
floods of melt gushed off the edge of the continent 
<https://www.nationalgeographic.com/environment/2019/07/greenland-melting-second-time-this-summer-bad/>_,_ 
and fires broke out in its sparse landscapes after a heat wave parked 
over the island for weeks.

There’s a lively scientific debate underway about whether these kinds of 
heat waves in the high latitudes are lasting longer 
<https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2017GL073395> 
or becoming more frequent than they were in the past because of climate 
change. But there’s little debate that the future holds much more 
extreme heat for the Arctic. Winter average temperatures in the Arctic 
have already exceeded the 3.6°F (2°C) threshold stated in the Paris 
climate agreement; predictions suggest the annual average temperature 
for the region will exceed that within decades.

"By 2100, under an extreme warming scenario, we would expect to see an 
event like this every year," says Robert Rohde, a climate scientist with 
Berkeley Earth. <http://berkeleyearth.org/team/robert-rohde/>

Similar patterns are playing out at the southern pole, too. A site on 
the Antarctic Peninsula hit nearly 65°F (18.3°C) during January, its 
summertime.


    *Polar amplification and human fingerprints*

The poles are warming up more quickly than the rest of Earth because of 
a phenomenon called “polar amplification.” The sea ice that used to 
blanket much of the Arctic Ocean provided a bright white cap across the 
northernmost reaches of the planet. Like the snow that reflects incoming 
solar radiation in Siberia, the ice bounced the sun’s heat back toward 
space.

But as Earth has warmed, there’s less sea ice covering the Arctic Ocean, 
leaving behind dark waters that absorb much more heat. Sea ice forms 
less readily in that warm water, leading the water to absorb even more 
solar heat, and the system goes on a self-reinforcing loop.

It’s difficult to say for sure that this or that single heat wave was 
worse because of climate change—and no one has yet done that analysis 
for this stretch of excessive Siberian warmth. But researchers found 
human-caused climate change’s fingerprints all over the heat wave that 
caused excessive melting in Greenland and across northern Europe last 
summer. 2019’s June heat—which caused temperatures in France to spike 
above 113°F (45°C), was at least five times more likely to occur because 
of human impacts 
<https://www.worldweatherattribution.org/wp-content/uploads/WWA-Science_France_heat_June_2019.pdf>. 
And some 60 percent of 2016’s excessive Arctic heat was attributable to 
human-caused climate change <http://nsidc.org/arcticseaicenews/2016/>, 
scientists found.


    *Fires, oil spills*

This season’s hot weather comes with consequences. Below the ground, 
much of the Russian Arctic is covered in permafrost, carbon-rich peat 
soils capped by a layer of ice that usually stays frozen for most or all 
of the year. But hot air temperatures destabilize the frozen ground and 
lead to often irreparable change.

(Read about how melting permafrost could supercharge climate change—in a 
very bad way 
<https://www.nationalgeographic.com/environment/2018/08/news-arctic-permafrost-may-thaw-faster-than-expected/>).

In June, defrosted soils may have led to the collapse of a diesel 
storage tank 
<https://www.theguardian.com/environment/2020/jun/09/russian-mining-firm-accused-of-using-global-heating-to-avoid-blame-for-oil-spill> 
in Siberia, spilling 20,000 metric tons of fuel into a nearby river. A 
recent study <https://www.nature.com/articles/s41467-018-07557-4> 
suggests that this is far from an isolated risk: By 2050, scientists 
say, vast amounts of infrastructure across the Arctic are at risk from 
thawing ground collapsing beneath them. Thousands of miles of pipelines 
and roads, buildings and storage tanks, oil fields and airports, and 
more, all potentially destabilized by overheated weather that has melted 
the ground.

Fires have also been smoldering across the Russian Arctic. The overwarm 
spring dried out both soils and vegetation, leaving them primed to burn, 
and over 12 million acres were on fire as of early June, according to 
Russia’s forest service 
<http://public.aviales.ru/main_pages/openform1.shtml?2020-06-02>.

“There’s lot and lots of vegetation and forest across Siberia,” says 
Meier. “And when it’s hot like this for so long, it dries out and 
becomes like a tinderbox


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