Arctic Climate Change: Where Reality Exceeds Expectations

Mark C. SerrezeNational Snow and Ice Data Center (NSIDC)Cooperative Institute for Research in Environmental Sciences at the University of Colorado at Boulder

Special Thanks: Julienne Stroeve, Andy Barrett, Ted Scambos, Drew Slater, Dave Lawrence, Tingjun Zhang

July, 1982: Global Warming? Bah!!

Ellesmere Island, near Lake Hazen

Peering into the future ….

Fi gure 10. 8

IPCC 2007

Arctic Amplification

Loss of Near-Surface Permafrost

Lawrence and Slater, 2005

Left: changes in multi-model mean freshwater budget terms for the Arctic Ocean with respect to 1950-1980 means: positive anomalies indicate an increasing source (or decreasing sink) of freshwater for the Arctic Ocean

Holland et al. 2007; Serreze et al. 2006

Acceleration of the Freshwater Cycle

Arctic sea ice is disappearing

Stroeve et al. 2008

Observed rate of loss is faster than expected

Adapted from Stroeve et al., 2007

The Northwest Passage: open by late August 2007

G. Spreen, L. Kaleschke, and G. Heygster/IUP Universitat Bremen, AMSR data from National Snow and Ice Data Center (left); unknown (upper right); Dave Kavanagh (middle right); D. Thoreson (lower right)

Manhattan1968

Gjoa1903

Cloud Nine2007

Impacts on Polar Bears

Model-Projected Arctic Amplification

Mark Serreze, Andy Barrett, Marika Holland

Model projection of 2-meter temperature anomalies by month and year for 70–90 degrees North latitude, compared to 1979–2007 means(CCSM3)

Latitude by height dependence of zonally averaged October–March temperature anomalies for 2050–2059, compared to 1979–2007 means(CCSM3)

Arctic amplification has emerged

Temperature anomalies, 2003–2007 minus 1979–2007

NCEP/NCAR, Climate Diagnostics Center

October

Observed Autumn Temperature Trends, 1960-2007

GISS Analysis

W. Abdalati

Greenland’s Changing Mass Budget

Surface Melt and the “Zwally Effect”

K. Steffen, M. Tedesco

Greenland’s Largest Glacier: Acceleration and Retreat

Ian Howat, Ian Joughin, Ted Scambos

Warming Permafrost

Russian Permafrost Temperature

-4

-3

-2

-1

0

1

2

3

4

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000Year

Te

mp

era

ture

De

par

ture

(°C

) 0.2 m; Trend = +0.78°C/decade0.4 m; Trend = +0.79°C/decade0.8 m; Trend = +0.65°C/decade1.6 m; Trend = +0.55°C/decade3.2 m; Trend = +0.66°C/decade

Alaska: 4 to 6°C increase in 20th Century, 2 to 3°C in the last 30 years

Siberia: >3°C increase from mid-1950s to 1990

Canadian Arctic: 1 to 3°C increase in past several decades

Tibetan Plateau: up to 1.0°C increase since 1970s

IPCC 2007

Infrastructure ImpactsChersky, Russia

Qinghai-Xizang Highway bridge collapse

Alaska

Thermokarst in Yakutsk, Russia (Skiklomanov, 2005).

Methane Release from Arctic Lakes

Burning methane over a thermokarst lake in Siberia (K. Walter)

Methane bubbles trapped in lake ice

Lakes boiling with methane in

the Arctic

Talik Formation

Active layer

Permafrost

Seasonally frozen layer

Permafrost

Talik

(layer of unfrozen ground)

Chandler River, 50 miles S. of Umiat: Sturm, Racine and Tape: Fifty Years of Change in Arctic Alaskan Shrub Abundance

1949

Changes in Shrub Abundance: Chandler River, AK

2001

Concluding Comments

Even our earliest climate models projected that effects of greenhouse gas loading would be seen first in the Arctic.

Even eight years ago, attribution of observed changes was uncertain.

Despite strong imprints of natural variability, a role of greenhouse greenhouse gas loading now seems clear

A number of key changes are exceeding expectations from climate models. Could we lose the summer sea ice cover by 2030?

Much remains to be understood—the idea of “tipping points” has emerged as a key issue.

Not everything is rapidly changing (hydrologic cycle).