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Arctic sea ice loss and warming: the long-term perspective
Jennifer Kay Assistant Professor, Atmospheric and Oceanic Sciences University of Colorado September 30, 2015
State of the Arctic
Sunday’s Arctic Sea
Ice Coverage
UCAR Congressional Briefing – September 2015
State of the Arctic
Russia
Alaska
UCAR Congressional Briefing – September 2015
State of the Arctic
Seasonal maximum in March Seasonal minimum in September
March 2015 September 2012
Data source: NSIDC
UCAR Congressional Briefing – September 2015
State of the Arctic
Arc,c sea ice is disappearing, especially in late summer!
Data source: NSIDC
UCAR Congressional Briefing – September 2015
State of the Arctic
Climate studies have long predicted Arc=c sea ice loss and greater-‐than-‐global Arc=c warming
“supercomputer” (1970s)
Manabe and Stouffer (1980): “The CO2-‐induced warming of the surface air is parDcularly large in
high laDtudes. “
What has happened since Manabe and Stouffer
(1980)?
UCAR Congressional Briefing – September 2015
State of the Arctic
Data source: GISTEMP
Warming globally and especially in
the Arctic
Why is Arctic warming 4x Global warming?
UCAR Congressional Briefing – September 2015
State of the Arctic
Less sea ice leads to darker ocean surface
More absorbed sunlight leads to
less sea ice
Darker ocean surface leads to more absorbed sunlight
Arctic positive feedbacks
Arctic warming is
more complex than a single
feedback.
UCAR Congressional Briefing – September 2015
State of the Arctic
Data source: MODIS
UCAR Congressional Briefing – September 2015
State of the Arctic
If someone asked me if sea ice is going to go up or down in the next 30 years…
…with con,nued greenhouse gas emissions, sea ice will disappear.
Take-home messages: 1. Arctic warming and sea ice loss predicted decades ago. 2. Sea ice is responsive to climate variability and change. 3. Remaining unknowns: long-term ice loss rate, short-term predictability.
UCAR Congressional Briefing – September 2015
State of the Arctic
