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Mark C. Serreze
Julienne Stroeve, Walt Meier, Ted Scambos,Marika Holland, Stephanie Renfrow, Matt Savoie
Cooperative Institute for Research in Environmental SciencesNational Snow and Ice Data CenterUniversity of Colorado, Boulder CO
Planet in Peril:Polar Ice Update
Courtesy NASA
Arapahoe Glacier, 1917
Arapahoe Glacier, 2004
Glaciers are retreating worldwide, including Colorado
The “greenhouse effect”
Fossil fuelsDeforestation
Fertilizers
Rice RuminantsLandfillsFossil fuel
the ‘Hockey Stick’ diagram
Overall radiative forcing: about 2 Watts/m2
1 light per square meter around the entire planet 500 Trillion Christmas lights On 24 hours a day, 365 days a year 600 x global electrical consumption
The Arctic should be especially sensitive to greenhouse
gas loading
Why?
Feedbacks!
Bellwether:
Bellwether (1) - One that serves as a leader or as a leading indicator of future trends
Bellwether (2) - Sheep that leads the herd often wearing a bell
Inuksuk:A stone landmark used as a milestone or directional marker
The Arctic Sea Ice Cover
•Observations document rapid sea ice loss
•This loss is already having impacts on the Arctic
•Will eventually have impacts beyond the Arctic
Downward trends in all months
(courtesy of Harry Stern, U. Washington)
Loss of the summer ice cover
22 states – almost entire US east of the Mississippi(courtesy of Dr. Don Perovich, CRREL)
SEA ICE THICKNESS
Spatial and Temporal Variability in Ice Age
• “AVHRR Polar Pathfinder (APP)”-derived ice age – estimated using Langrangian tracking of ice drift estimated from APP ice motion fields (Fowler et al., 2003).
Shishmaref, AK
Shishmaref, AK
October 2002 storm
Photos taken ~2 hours apart
Credit: Tony Weyiouanna Sr.
The fabled NorthwestPassage is open in late August 2007!
Photo D. Kavanagh
Peering into the future…
Implications of this change in surface state
Absorbedsunlight Lower albedo
Melting
+
++
An amplifier of climate change
Back in the 1970s ….
Not far from today…
Peering into the future… Amplified warming in the Arctic
Impacts on middle-latitude climate? Colorado?
Recent Surface Temperature Changes
Autumn/WinterAnnual
Last Eight Years Compared to 1979-1999
Autumn/Winter: Up to 5 degrees C (9 degrees F)
Observed Sea Ice Decline: Faster than Forecast
Compiled by NSIDC
As the sea ice cover continues to retreat, the Arctic will become increasinglyaccessible, not just tocommercial shipping, but tooil extraction.
The irony is obvious
What can we do?
•Some further warming is already “in the pipeline”
•Key: keep things from getting out of hand
•Conservation, conservation, conservation!!!
•Vigorously promote cleaner technologies
•Solar, wind, carbon sequesteration
•Geo-engineering?
•Nuclear?
Humankind will rise to the challenge
•We must adapt
Questions?