Climate Change: Past, Present, and Future

Dr. Cameron WakeClimate Change Research CenterInstitute for the Study of Earth, Oceans, and Space (EOS)University of New Hampshire

2006 Boston World Oil Conference26 Oct 2006

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1960 1970 1980 1990 2000

Mauna Loa (Hawaii) Carbon Dixoide Record 1958 - 2004

CO2 (ppmv)

year

http://cdiac.esd.ornl.gov/

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1000

0100,000200,000300,000400,000Years Before 2100 AD

Vostok Ice Core

Petit et al., 1999

Atmospheric Carbon Dioxide

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0100,000200,000300,000400,000Years Before 2100 AD

Vostok Ice Core Current (2005)

Mauna Loa

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1960 1970 1980 1990 2000

Mauna Loa (Hawaii) Carbon Dixoide Record 1958 - 2004

CO2 (ppmv)

year

http://cdiac.esd.ornl.gov/

Atmospheric Carbon Dioxide

200

400

600

800

1000

0100,000200,000300,000400,000Years Before 2100 AD

Vostok Ice Core Current (2005)

Mauna Loa

Projected (2100)IPCC 2001 - A1FI

IPCC 2001

Atmospheric Carbon Dioxide

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400

600

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0100,000200,000300,000400,000Years Before 2100 AD

Vostok Ice Core Current (2005)

Mauna Loa

Projected (2100)IPCC 2001 - A1FI

Atmospheric Carbon Dioxide

IPCC 2001

Projected (2100)IPCC 2001 - B1

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1880 1900 1920 1940 1960 1980 2000

Annual Mean5-year Mean

Year

http://www.giss.nasa.gov

Global Temperature 1880-2005(meteorological stations)

Time-series represents an aerially weighted average of data from 136 stations. Data from the NOAA-NCDC and Environment Canada

Average Annual Temperature in NE US & CDN Maritimes 1900-2002

1.4 oF warming over 103 years1.8 oF warming over 33 years

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1900 1920 1940 1960 1980 2000

Temperature (

oF)

Year

The temperature trend was calculated from a linear regression of annual average temperature for each station.

Spatial Variation of Annual Temperature Trend 1970-2002

Average Winter Temperature in the NE US & CDN Maritimes 1900-2002

Time-series represents an aerially weighted average of data from 136 stations. Data from the NOAA-NCDC and Environment Canada

2.3 oF warming over 103 years4.3 oF warming over 33 years

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1900 1920 1940 1960 1980 2000

Temperature (

oF)

Year

4.3oF Winter Temperature Increase from 1971-2002

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29 30 31 32 33 34 35 36 37

Latitude (

o N)

Winter (DJF) mean Temperature (oF)

Boston

New York

Philadelphia

Washington, DC

Spatial Variation of Extreme Precipitation Trend 1970-2002

The extreme precipitation trend was calculated from a linear regression of number of events each year for each station.

Spatial Variation of Days with Snow on Ground 1970-2002

The snow on ground trend was calculated from a linear regression of annual total snow on ground days for each station.

Northeast Climate Impacts Assessment (NECIA)

• Collaboration between UCS and 40 independent scientists

• Analytic ApproachAssess projected changes in climate and potential impacts through 2100 under lower and higher scenarios of heat-trapping emissions.

• Geographic ScopeNine Northeast states, from Maine to Pennsylvania.

• Peer ReviewK. Hayhoe, C. Wake, et al.,

Climate Dynamics, in pressBAMS, in review

Greenhouse Gas Emission Scenarios

Northeast Observed and Modeled Temperature

Northeast Observed and Modeled Precipitation

Northeast Observed and Modeled Extreme Temperature

Northeast Observed and

Modeled Drought

Northeast Observed and Modeled Snow on Ground Days per Month

Higher emissions: 50% reduction in snow-covered days (shown here)

Lower emissions: 25% reduction in snow-covered days

Northeast Modeled Snow on Ground Days

Sea Level Rise

-20

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1900 1925 1950 1975 2000 2025 2050 2075 2100projected global mean sea level rise (cm))

Higher emissions

Lower emissions

uncertainty in SLR from thermal expansion

uncertainty in SLR from ice melt

These estimates do not include the potential for additional increases due to more rapid melting of major polar ice sheets.

Higher: 8-33 inches

Lower: 4-21 inches

Conclusions

• Climate is already changing across the Northeast• Over the next few decades, similar changes expected under

both emissions scenarios• By mid-century, most changes are greater under the higher

scenario• By late-century, under the higher-emissions scenario:

– Many changes are almost twice those seen under lower emissions, including:

– winters warming by 8 -12F and summers by 6 -14F, with dramatic increases in extreme heat in cities.

Time For Action

• Individuals

• Institutions

• Citizens

Observed vs. Modeled Global Temperatures 1850-2000

From IPCC Climate Change 2001: The Scientific Basis (http://www.ipcc.ch)

(solar variations and volcanic activity)

Observed vs. Modeled Global Temperatures 1850-2000

From IPCC Climate Change 2001: The Scientific Basis (http://www.ipcc.ch)

(Greenhouse gases and sulfate aerosols)

From IPCC Climate Change 2001: The Scientific Basis (http://www.ipcc.ch)

Observed vs. Modeled Global Temperatures 1850-2000

Two roads diverged in a wood, and I - I took the one less traveled by, And that has made all the difference.  

What path will we take to the future?

Robert Frost