Jennifer Kay, Assistant Professor, Atmospheric and Ocean Sciences, University of Colorado - September 2016 UCAR Congressional Briefing Arctic sea ice is disappearing, especially in late summer. Climate studies have long predicted this, along with more-than-average warming in the region. Why is the Arctic warming four times more than the global average temperature increase? What else do we need to understand about the relationship between climate change and the Arctic? Video of this presentation: https://president.ucar.edu/government-relations/washington-update/851/state-arctic-ucar-congressional-briefing

1. 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

2. Sunday’s
Arctic Sea
Ice Coverage
UCAR Congressional Briefing – September 2015
State of the Arctic
Russia
Alaska

3. UCAR Congressional Briefing – September 2015
State of the Arctic
Seasonal
maximum
in
March
Seasonal
minimum
in
September
March
2015
September
2012
Data
source:
NSIDC

4. UCAR Congressional Briefing – September 2015
State of the Arctic
Arc,c
sea
ice
is
disappearing,
especially
in
late
summer!
Data
source:
NSIDC

5. 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.
“

6. 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

7. 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

8. Arctic
warming is
more
complex
than a
single
feedback.
UCAR Congressional Briefing – September 2015
State of the Arctic
Data
source:
MODIS

9. 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.

10. 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