Ice Core Paleoclimate Research Group

Lonnie G. ThompsonHenry BrecherMary DavisPaolo GabrielliPing-Nan LinMatt MakouVictor Zagorodnov

Understanding Global Climate and Environmental Change

Ellen Mosley-Thompson, Professor (Atmospheric Science)Director, Byrd Polar Research Center

The Ohio State University, Columbus Ohio, USA

Funding provided by: NSF: Paleoclimate and Polar Programs NASA: Earth Sciences (Glaciology) NOAA: Paleoclimatology Gary Comer Foundation OSU Climate, Water & Carbon Program

Graduate Students: Liz Birkos Aron Buffen Natalie Kehrwald David Urmann Lijia Wei

The Human Footprint on Earth Image: NASA

http:www.giss.nasa.gov/research/news

Our Earth is warming!

- some changes are unprecedented for thousands of years

- some changes are occurring rapidly (years to decades)

rapid changes can pose severe challenges for adaptation

Environmental conditions are changing!

2005 warmest year on record

0.75°C

(◦C) Year A.D.

Global Temperature Change (ºC).6

.4

.2

0

-.2

-.4

1880 1900 1920 1940 1960 1980 2000

Year A.D.

relative to the 1951-1980 mean

2001-2007 Mean Surface Temperature Anomaly (◦C) Global .54

relative to the 1951-1980 mean

ºC

Climate is changing differently across the globe!

Natural mechanisms influence climate

• Changes in the Sun

• Changes in the amount of volcanic aerosols in the atmosphere

• Internal variability of the coupled atmosphere-ocean system (e.g., ENSO, monsoon systems, NAO)

Natural mechanisms

Human factors also influence climate

Non-natural mechanisms

• Changes in the concentrations of atmospheric greenhouse gases

• Changes in aerosols and particles from burning fossil fuels (sulfate aerosols) and biomass (black carbon)

• Changes in the reflectivity (albedo) of the Earth’s surface

Smoke from fires in Guatemala and Mexico (May 14, 1998)

?? Pre-anthropogenic level

Lüthi et al., Nature,May 15, 2008

Today:

CO2 is 378 ppmv

CH4 is 1750 ppbv

Today:

CO2 is 387 ppmv

CH4 is 1800 ppbv

Thousands of Years (B.P.)

800 600 400 200 0

387

1800

850

3700IPCC 2000Scenario A1Bfor 2100 AD

CO2 remains in theatmosphere from70 to 120 years

Carbon Dioxide & Methane Concentrations Past, Present and Future

Dome C

EPICA Dome C ice core extends back

through eight glacial and interglacial

stages (800,000 years) recording changes

in the composition of Earth's atmosphere

- Recent and rapid melting of glaciers in non-polar regions around the world

Many observed changes that are broadly consistent with an increase

in the radiative heating of Earth’s surface and lower atmosphere

Climatologically we are in unfamiliar territory,

and the world’s ice cover is responding dramatically.

Gangapurna Glacier

1957

~ 2 - 3 m thinning / yearCourtesy Doug Burbank, UCSB

Massive retreat of low-latitude glaciers today

2002

Quelccaya Ice Cap, Peru1977 2002

L.G. Thompson, OSU L.G. Thompson, OSU

Kilimanjaro has lost 85%

of its ice cover since 1912

Thompson et al., PNAS, 2009, in press, November issue

- Increase in global ocean surface temperatures of 0.35°C since 1979

- warming evident at all latitudes over all ocean basins

- to depths of at least 3000 meters

Many observed changes that are broadly consistent with an increase

in the radiative heating of Earth’s surface and lower atmosphere

- Decreases in the area covered by seasonally frozen ground in

the high northern latitudes

- Reduction by about 2 weeks of the annual duration of northern lake

and river ice

- Recent and rapid melting of glaciers in non-polar regions around the world

- Dramatic decreases in the areal coverage and thickness of Arctic sea ice

- Rising sea level

- Increases in atmospheric moisture content (increased evaporation)

- Changes in extremes are consistent with warming

- increase in heat waves globally

- widespread increase in warm nights

- rarer occurrences of cold days, cold nights and days with frost

These many independent observations and the physical consistency

among them form the basis for the 2007 conclusion by the

Intergovernmental Panel of Climate Change (IPCC) that

“warming of the climate is unequivocal”

Many observed changes are broadly consistent with an increase

in the radiative heating of Earth’s surface and lower atmosphere

“ Warming of the climate system is unequivocal”

“Most of the observed increase in globally averaged temperaturessince the mid-20th century is very likely* due to the observed increasein anthropogenic greenhouse gas concentrations.”

* Very likely means 90% confidence

A 3-year effort152 authors (30 countries)> 600 reviewersApproved by 113 governments

observations

Global and Continental Temperature Change from 1900 to 2000 AD

natural forcingsonly

natural and anthropogenic

forcings

IPCC Fourth Assessment February 2007

4

3

5

0

Glo

bal

Tem

pera

ture

(°C

)

N.H. Temperature (°C)

IPCC 4th Assessment (2007)Projection for 2100 AD

2.0 – 4.5 oC

1000 1200 1400 1600 1800 2000Year (A.D.)

2

1

0

0.4

-0.4

-0.8

Year A.D..

Northern Hemisphere temperature (°C)

for the last 1000 years

4

3

5

0

Glo

bal

Tem

pera

ture

(°C

)

1000 1200 1400 1600 1800 2000Year (A.D.)

2

1

0

0.4

-0.4

-0.8

Year A.D..

Global average surface

temperature is heading not only

far outside the range of variation

of the last 1000 years but

outside the range experienced in

the tenure of Homo sapiens on

Earth.

Future energy policy will determine this

This warming has already occurred

Recent Assessments

http://www.ostp.gov/galleries/NSTC Reports/Scientific Assessment FULL Report.pdf

Report of the Committee on Environmentand Natural Resources

National Science and Technology CouncilMay 2008

http://www.climatescience.gov/Library/sap/sap4-3/final-report/default.htm

Report from U.S. Climate Change Science Program 2008

http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts

Recent Assessment

2009