14 | New Scientist | 13 July 2019
DOZENS of wildfires have been
raging across the Arctic circle
for the past few weeks, releasing
as much carbon dioxide in just
one month as Sweden’s total
annual emissions.
Fires in the region aren’t
unknown, but the scale of the
blazes, predominantly in boreal
peatlands across Siberia, is
unprecedented. Satellite
measurements show that the
energy released by the fires in June
is more than that produced during
the previous nine Junes combined.
“It’s quite striking, it does really
stand out,” says Mark Parrington
at the European Centre for
Medium-Range Weather Forecasts.
The last time the region had
such big fires was 15 years ago.
The driver for the fires seems
to be the unusually high
temperatures in June, the hottest
one on record in Europe. The
Arctic was also warmer than
average. “It’s hotter and drier. If
the temperature is high enough
and there’s ignition, fuel burns,”
says Parrington.
The size of the burning area isn’t
clear. Thomas Smith at the London
School of Economics says satellite
photos suggest that some fires arebigger than 100,000 hectares,
which would classify them as
megafires. There are signs they are
still burning, although detection
is hampered by cloud cover. “Some
hotspots are apparent through
gaps in clouds, which suggest
fires are continuing,” he says.The fires seem to be mostly
on carbon-rich peatland.
Parrington calculates that the
wildfires in June released about
50 megatonnes of CO 2 , on par
with Sweden’s total emissions in- That CO 2 will lead to more
warming, in a feedback loop.
The blazes also seem to be
accelerating climate change by
depositing soot and ash on sea ice.
Satellite photos in June show sea
ice in the Laptev Sea and East
Siberian Sea turning darker, which
will exacerbate melting, in turn
bringing more warming because
the sea is darker than ice and so
absorbs more of the sun’s energy.
The Arctic wildfires are in line
with predictions made a decade
ago, when researchers said they
expected the region – which is
warming faster than the rest of the
world – to see some of the biggest
increases in fires. “What we might
be seeing this year is widespread
breach of a critical temperature
threshold, leading to such
widespread fires,” says Smith.
“The term ‘Arctic fire’ is a
relatively new arrival to science
and still causes consternation.
It isn’t part of common sense yet,”
says Guillermo Rein of Imperial
College London.
What started these fires isn’t
known, but given how sparsely
inhabited the region is, lightning
is thought to be a likely cause.
Meanwhile, at least 18 people
were killed in the Siberian region
of Irkutsk after severe flooding
caused by heavy rainfall. A state
of emergency was declared and
Russian military personnel sent
to the region. ❚Extreme weatherAdam VaughanKIRILLSHIPI
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VIAGETTY^ IMAGESNews
The Arctic is on fire
Unusual wildfires are releasing huge amounts of carbon dioxide
Chris Stokel-WalkerSome Arctic fires seem
large enough to be
classed as megafiresSocial mediaYOUTUBE’S recommendation
algorithm steers people to more
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popular sites. The other two were
Gab, a social-media site favoured
by people on the far-right, and
Reddit, a news aggregation site.
Joe Whittaker at Swansea
University, UK, and his colleagues
analysed how personalisationalgorithms on the three sites
recommend content.
They made three YouTube
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neutral content, one mainly on
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the homepage and was twice as
likely to be recommended than it
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The neutral-interacting account saw
extreme content once in every five
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posts of each category had no
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“If you engage with something,
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videos, music or extremist
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Terrorism and Social Media
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de Keulenaar at the University of
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YouTube told New Scientist that
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but it is reducing their prominence.
During the analysis, YouTube said
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Changes are ongoing, but only a
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