870 gigatons
of carbon
in atmosphere
1,600 gigatons
in permafrost
Active layer
Permafrost
A LANDSCAPE
REVOLUTION
As ice buried within frozen ground melts, the
meltwater moves through the permafrost, thawing it
further and causing the ground above it to slump.
Ponds form and later drain, hastening the collapse of
even more frozen soils. The process is called abrupt
thaw, and it’s accelerating the release of trapped
carbon—and visibly changing the Arctic.
BURNING TUNDRA
Tundra fires, once rare, are becoming
more common as a warming climate
greens the Arctic. Fires thaw the top
layer of soil and rapidly degrade
the permafrost below.
How polygonal permafrost forms—and thaws
Growing ice wedges push soil
upward, forming
polygonal patterns.
Water fills in the cracks, which freeze
and expand, form-
ing ice wedges.
JASON TREAT, MATTHEW W. CHWASTYK, AND RYAN WILLIAMS, NGM STAFF SOURCES: DAVID OLEFELDT AND OTHERS, NATURE COMMUNICATIONS, 2016;
MERRITT TURETSKY AND OTHERS, UNIVERSITY; TED SCHUUR, NORTHERN ARIZONA UNIVERSITY; EPANATURE, 2019; RÓISÍN COMMANE, COLUMBIA
JASON TREAT, RYAN WILLIAMS, AND EVE CONANT, NGM STAFFART: TOMÁŠ MÜLLER. SOURCES: KEN TAPE AND ANNA LILJEDAHL, UNIVERSITY OF ALASKA FAIRBAN
Greater than 400
300-400
200-299
100-199
Less than 100
GradualthawAbruptthaw
Carbon content (in tons per acre)in permafrost susceptible to:
Powering 43.5 average U.S. homes for a year releases
about 400 tons of carbon.
ARCTIC OCEAN
ATLANTIC OCEAN
PACIFIC
OCEAN
Hudson
Bay
Gulf of
Alaska
BaffinBay
LabradorSea
BeaufortSea
E. SiberianSea
Bering Sea OkhotskSea of
Gre
enl
an
d^ S
ea
Ka
ra
Se
a
BarentsSea
No
rw
egi
an^
Sea
Ambarchik Bay
BaikalLake
PLEISTOCENEPARK
Cherskiy
Fairbanks
Kaktovik
Newtok
Lakselv
S I B E R I A
ElizabethQueen
Islands
Parr
y^ Is.
Baffin
Isla
nd
Banks I.
Victoria I.
Batagaikacrater
Broo
ks^ Ra.
NORTH
AMERICA
A
S
I
A
EU
R
O
P
E
CANADA
ICELAND
(U.S.)
NORWAY
DENMARK
RUSSIA
SW
EDE
N
FINL
AND
GREE
NLA
ND
(KALA
ALLIT
NUN
AAT)
(DEN
MAR
K)
ALASKA
North Pole
ARCTIC CIR
CLE
0 °
60 °
30 °E
30 °W
60 °
60 °
90 ° 90 °
120 °
120 °
150 °W 180 ° 150 °E
The active layer freezes in winter,
creating cracks
deep in the soil.
THE THAW SPEEDS UP
The unexpectedly rapid collapse of ice-rich permafrost
in the Arctic could pump billions of additional tons of
methane and carbon dioxide into the atmosphere every
year—a threat that has yet to be fully accounted for in
climate models. Scientists are discovering destabilized
landscapes where permafrost that once thawed a few
inches a year can now abruptly thaw up to 10 feet within
days or weeks, creating wetlands in once frozen regions
and accelerating emissions from up to 1,600 gigatons
of carbon still locked underground.
Thawing fast and slow
Twenty percent of permafrost is ice rich and at risk of abrupt
thaw, which could double
the amount of greenhouse
gases released.
SCENES OF THAWING