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?