38 | New Scientist | 31 August 2019
Features
T
HE Arctic is in a death spiral. The top
of our world is heating up faster than
anywhere else on the planet, setting
new records for the speed and area of ice melt.
We are on track this year to have one of the
lowest summer sea ice coverages so far. It is a
huge problem, because what happens in the
Arctic doesn’t stay in the Arctic.
What’s more, the Greenland ice sheet, which
alone contains enough water to raise global sea
levels by 6 metres, is disappearing. The frozen
Arctic soil and sediment, or permafrost, is
melting, releasing more and more carbon
dioxide and methane into the atmosphere.
This year, vast wildfires in the peatlands of
Siberia have blazed for more than a month,
and the Arctic warming is playing havoc with
weather systems in the northern hemisphere
too. But if you prefer to think simply in terms
of money, the economic impact of unmitigated
Arctic warming by the end of this century was
recently estimated to be $67 trillion. As US
congressman Jerry McNerney says: “When it
comes to the Arctic, we’re in deep shit.”Arctic
rescue
squad
If we want to save the
Arctic, we might have to
intervene directly. Rowan
Hooper investigates three
ambitious projects to
bring back the ice
You’ve heard the slogans: we are living in a
time of climate emergency. But it is no good
declaring an emergency without summoning
help. So here it is: let’s refreeze the Arctic. There
are several imaginative ideas to manipulate its
climate system to get the ice back. They won’t
be cheap or easy, but some researchers argue
that the crisis in the north is too serious not to
at least investigate ways to engineer the return
of the ice.
Climate intervention in the Arctic might be
more necessary than it first appears because
the region’s death spiral is a feedback loop.
As the shiny ice melts, models and satellite
images suggest we could get a sea ice-free
summer any year now. When the ocean is
exposed, instead of reflecting sunlight, the
dark water absorbs more of the sun’s heat. Over
the past 30 years, this change corresponds to a
warming equivalent to a quarter of all the
carbon dioxide released by human activity
during that time. The warming is weakening
the polar jet stream – the fast-flowing, high-
altitude air current – in the northern