by 2050, and develop technologies to suck huge
quantities back out of the atmosphere.
The challenge may be even starker. The
1.5-degree report was the first time the IPCC had
taken permafrost emissions into account—but
it didn’t include emissions from abrupt thaw.
Climate models aren’t yet sophisticated enough
to capture that kind of rapid landscape change.
But at National Geographic’s request, Katey
Walter Anthony and Charles Koven, a modeler
at the Lawrence Berkeley National Laboratory,
made rough calculations that do add in emis-
sions from abrupt thaw. To halt temperature
rise at 1.5 degrees, they estimate, we’d have to
zero out our own fossil fuel emissions at least
20 percent sooner—no later than 2044, six years
ahead of the IPCC timetable. That would give us
just a quarter century to completely transform
the global energy system.
“We’re facing this unknown future with an
incomplete set of tools,” Koven said. “The uncer-
tainty isn’t all on our side. There are a lot of ways
things could turn out worse.” There’s more than
one way to make new lakes, for example.
FEW WEEKS AFTER LEAVING
Siberia, Orlinsky and I
took a raft trip through
Alaska’s Gates of the
Arctic National Park
with ecologist Ken Tape,
a colleague of Walter
Anthony’s at the Uni-
versity of Alaska. A floatplane dropped us and
river guide Michael Wald at Gaedeke Lake, in the
central Brooks Range. From there we made our
way south down the Alatna River. September
sun danced on the water. Within a mile or so we
found chewed sticks along the bank. We’d been
on the river a week when we arrived at a 38-acre
lake that hadn’t been there before. At its center
was an enormous beaver lodge.
Tape has been using aerial and satellite photo-
graphs for years to track how plants and wildlife
are changing in Alaska—and how that might
affect permafrost. As permafrost thaws and the
growing seasons lengthen, the Arctic is green-
ing: Shrubs in Alaska river plains, for example,
have nearly doubled in size. (While vegetation
growth will take up more carbon, a 2016 survey
of experts concluded that Arctic greening won’t
be nearly enough to offset permafrost thaw.) The
vegetation is drawing animals north.
The crumbling perma-
frost cliffs at Newtok,
on the Ninglick River
near the Bering Sea, are
now within a few dozen
feet of some homes.
The village is moving
to a new site nine miles
upriver—pioneering
a process that many
Alaskan villages may
one day undergo.94 NATIONAL GEOGRAPHIC