B. Holt - JPL

Ben HoltOceans-Ice Group

Jet Propulsion LaboratoryArctic Ocean, 1982

Climate Change in Earth’s

Polar Regions

B. Holt - JPL

Global Temperature Change Enhanced at Poles

Average 2001-2007 Surface Temperature Change,Relative to the 1951-1980 Average (◦C)

B. Holt - JPL

Sunlight Reflectivity on Ice and Ocean

•Increased warming => less ice => more open water => warmer water =>more ice melt and so on

Reflected 85%

Sunlight 100 %

Reflected 7%

Sunlight 100 %

B. Holt - JPL

Arctic and AntarcticIce as key indicator of climate change

/

Barrow, Alaska +30°F

South Pole-80°F !!

Sea Ice (colored) and Land Ice (white)

B. Holt - JPL

Arctic Sea Ice – Reduced Extent

11.5 % Reduction Per Decade since 1979

September 19, 2010

Satellite Record

B. Holt - JPL

Arctic Sea Ice ThicknessSubmarine and Satellite Record 1958-2007

Reference: Kwok & Rothrock, Geophysical Research Letters, 2009

•Sea ice thickness shows decadal thinning – over 40 %

B. Holt - JPL

Land Ice Glaciers, Greenland, Antarctica

~Water stored above sea level

B. Holt - JPL

Greenland Ice Mass Loss 2002-2009 Derived From NASA GRACE Gravity Mission

Greenland

Cha

nge

in I

ce M

ass

Los

s G

igat

ons

J. Wahr, U. Colorado

Velicogna, Geophysical Research Letters, 2009

•Contributes to sea level rise

B. Holt - JPL

2009 NOAA Arctic Report Card

B. Holt - JPL

Backup

B. Holt - JPL

Evidence and Impact of Arctic Warming

•Sea ice – thinning (>40%) and shrinking (11.5% / decade)

•Permafrost melting – also releases methane

•Land ice melting – sea level change

•Loss of sea ice – impacts habitat of polar bears, walruses

•Ecosystem shifts – from Arctic to subarctic communities

•Increase human activities – shipping and oil production

B. Holt - JPL

Sources, References

http://arctic.atmos.uiuc.edu/cryosphere/http:www.giss.nasa.gov/research/news

http://nsidc.orghttp://www.arctic.noaa.gov/reportcard/