The Current State of Our Climate Prof. Tim Raymond Chemical Engineering Dept. Bucknell University Focus the Nation – Obstacles to Change January 31, 2008.

The Current State of Our The Current State of Our ClimateClimate

Prof. Tim RaymondProf. Tim RaymondChemical Engineering Dept.Chemical Engineering Dept.

Bucknell UniversityBucknell UniversityFocus the Nation – Obstacles to ChangeFocus the Nation – Obstacles to Change

January 31, 2008January 31, 2008

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History and BackgroundHistory and Background

• 1800’s - CO1800’s - CO22 at 290 ppm; T = at 290 ppm; T = 13.6°C13.6°C• 1824 - Fourier discovers 1824 - Fourier discovers naturalnatural

‘greenhouse effect’ of atmosphere‘greenhouse effect’ of atmosphere• 1896 - Swedish scientist Arrhenius 1896 - Swedish scientist Arrhenius predictspredicts

‘greenhouse warming’ from CO‘greenhouse warming’ from CO22

• 1960 - CO1960 - CO22 at 315 ppm (up 9% from 1800) at 315 ppm (up 9% from 1800)• 1970’s - Unusual weather creates 1970’s - Unusual weather creates

speculationspeculation on global warming/cooling on global warming/cooling

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History and BackgroundHistory and Background

• 1981 – Hansen shows previous cooling 1981 – Hansen shows previous cooling trend was from trend was from aerosolsaerosols (pollution) (pollution)

• 1985 – Ice cores confirm 1985 – Ice cores confirm correlationcorrelation of CO of CO22 and temperatureand temperature

• 1990 - First IPCC report: world has been 1990 - First IPCC report: world has been warming and warming and future warming seems likelyfuture warming seems likely

• 1995 - Second IPCC report detects 1995 - Second IPCC report detects "signature" of "signature" of human-causedhuman-caused greenhouse greenhouse effect warming effect warming

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History and BackgroundHistory and Background

• 2001 - Third IPCC report: 2001 - Third IPCC report: unprecedentedunprecedented global warming global warming

• 2002 - Studies find surprisingly strong 2002 - Studies find surprisingly strong "global dimming" (pollution) has "global dimming" (pollution) has maskedmasked intensity of greenhouse warmingintensity of greenhouse warming

• 2005 - Kyoto treaty goes into effect2005 - Kyoto treaty goes into effect• 2007 - Fourth IPCC report: 2007 - Fourth IPCC report: unequivocal unequivocal

warmingwarming

• 2007 - CO2007 - CO22 at 382 ppm; T = at 382 ppm; T = 14.5°C 14.5°C (up (up 32%)32%)

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Annual Average Global Surface Temperature Anomalies 1880-2006

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Annual Average Global Surface Temperature Anomalies 1880-2006

Cooling from Pollution

WarmingWarming

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Scientists know with virtual Scientists know with virtual certainty that:certainty that:• Human activities are changing the Human activities are changing the

composition of Earth's atmosphere.composition of Earth's atmosphere.• The atmospheric buildup of COThe atmospheric buildup of CO22 and other and other

greenhouse gases is largely the result of greenhouse gases is largely the result of human activities.human activities.

• An “unequivocal” warming trend of about An “unequivocal” warming trend of about 1.0 to 1.7°F occurred from 1906-2005. 1.0 to 1.7°F occurred from 1906-2005.

• The major greenhouse gases emitted by The major greenhouse gases emitted by human activities remain in the atmosphere human activities remain in the atmosphere for periods ranging from decades to for periods ranging from decades to centuries. centuries.

• Increasing greenhouse gas concentrations Increasing greenhouse gas concentrations tend to warm the planet. tend to warm the planet.

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Body of EvidenceBody of Evidence

• Increase of global average air temperatureIncrease of global average air temperature

• Increase is ocean water temperaturesIncrease is ocean water temperatures

• Decrease in Arctic sea-ice extent/thicknessDecrease in Arctic sea-ice extent/thickness

• Decrease in glacier/ice cap extent/massDecrease in glacier/ice cap extent/mass

• Rising global mean seal levelRising global mean seal level

• Changes in freeze/thaw, precipitation, etc. Changes in freeze/thaw, precipitation, etc.

1/31/081/31/08 Bucknell UniversityBucknell University 1111FAQ 9.2, Figure 1

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Other Climate VariablesOther Climate Variables

• Oceans are becoming more acidic (COOceans are becoming more acidic (CO22))

• ““Observational evidence from all Observational evidence from all continents and most oceans shows that continents and most oceans shows that many natural systems are being affected”many natural systems are being affected”– Permafrost: melting, instability, ecosystemsPermafrost: melting, instability, ecosystems– Ecosystems: early spring, animal rangesEcosystems: early spring, animal ranges– Migrations: timing and extentMigrations: timing and extent

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What’s Not Certain?What’s Not Certain?

• How How muchmuch warming will occur warming will occur

• How How fastfast it will occur it will occur

• How the warming will How the warming will affect the rest affect the rest of the climate systemof the climate system

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Summary of Current StateSummary of Current State

• ““Warming of the climate system is Warming of the climate system is unequivocal”unequivocal”

• Directly related to human activitiesDirectly related to human activities

• Directly related to increases in GHGsDirectly related to increases in GHGs

• Global effects already visibleGlobal effects already visible

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SourcesSources• http://www.aip.org/history/climate/timeline.htmhttp://www.aip.org/history/climate/timeline.htm

• Observations of climate change: The 2007 IPCC Observations of climate change: The 2007 IPCC Assessment, Testimony of Dr. Kevin E. Trenberth, Assessment, Testimony of Dr. Kevin E. Trenberth, Committee on Science and Technology, United States Committee on Science and Technology, United States House of Representatives, February 8, 2007House of Representatives, February 8, 2007

• IPCC, 1996: Climate Change 1995: The Science of Climate IPCC, 1996: Climate Change 1995: The Science of Climate Change. Eds. J. T. Houghton et al., Cambridge University Change. Eds. J. T. Houghton et al., Cambridge University Press, Cambridge, U.K. 572 pp.Press, Cambridge, U.K. 572 pp.

• IPCC, 2001: Climate Change 2001: The Scientific Basis. Eds. IPCC, 2001: Climate Change 2001: The Scientific Basis. Eds. J. T. Houghton, et al., Cambridge University Press, J. T. Houghton, et al., Cambridge University Press, Cambridge, U.K. 881 pp.Cambridge, U.K. 881 pp.

• IPCC, 2007: Climate Change 2007: The Scientific Basis. Eds. IPCC, 2007: Climate Change 2007: The Scientific Basis. Eds. S. Solomon, et al., Cambridge University Press, Cambridge, S. Solomon, et al., Cambridge University Press, Cambridge, U.K. (in press).U.K. (in press).

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SourcesSources• http://www.epa.gov/climatechange/science/index.htmlhttp://www.epa.gov/climatechange/science/index.html