Global and Regional Climate Change: What on Earth are We Doing?!

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

Global and Regional Climate Change: What on Earth are We Doing?!

Eugene S. TakleAgronomy Department

Geological and Atmospheric Science Department

Iowa State University

Ames, Iowa 50011

[email protected]

Ames Golden K Kiwanis, 10 February 2005


Outline Evidence for global climate change Future atmospheric carbon dioxide concentrations Simulations of global climate and future climate

change Impact on global food production and fresh-water

availability Implications for the Midwest “Dangerous anthropogenic interference

with the climate system”? What can I do?

Carbon Dioxide and Temperature


2004


2004

2040


Stabilization at 550 ppm


“Business as Usual”(fossil intensive)

2100


Associated Climate Changes

Global sea-level has increased 1-2 mm/yr Duration of ice cover of rivers and lakes decreased by 2 weeks in N.

Hemisphere Arctic ice has thinned substantially, decreased in extent by 10-15% Reduced permafrost in polar, sub-polar, mountainous regions Growing season lengthened by 1-4 days in N. Hemisphere Retreat of continental glaciers on all continents Poleward shift of animal and plant ranges Snow cover decreased by 10% Earlier flowering dates Coral reef bleaching

Source: Intergovernmental Panel on Climate Change, 2001 Report

Mann, M. E., R. S. Bailey, and M. K. Hughes, 1999: Geophysical Research Letters 26, 759.

Source: IPCC, 2001: Climate Change 2001: The Scientific Basis

Source: IPCC, 2001: Climate Change 2001: The Scientific Basis

NASA photographs show the minimm Arctic sea ice concentration in 1979 at left and in 2003.Satellite passive microwave data since 1970s indicate a 3% decrease per decade in arctic sea ice extent.

Since 1979, the size of the summer polar ice cap has shrunk more than 20 percent. (Illustration from NASA) (http://www.nrdc.org/globalWarming/qthinice.asp)




Hansen, Scientific American, March 2004

Mt. Pinatubo (1991)

El Chichon (1982)Agung, 1963

Source: Jerry Meehl, National Center for Atmospheric Research

Source: National Center for Atmospheric Research

Source: National Center for Atmospheric Research

The planet is committed toa warming over the next 50 years regardless of political decisions


40% Probability

5% Probability


Climate Change Projected for 2100

Rapid Economic Growth

Slower Economic Growth

Source:

Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment (www.acia.uaf.edu) Cambridge University Press (www.cambridge.org).

http://www.acia.uaf.edu/

Areas subjected to Inundation with a 1 m(~3 ft) rise in sea level

Kennedy SpaceCenter

Miami

Impact of a 1-mrise in sea levelon low-lying areas

Source:

Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment (www.acia.uaf.edu) Cambridge University Press (www.cambridge.org).

http://www.acia.uaf.edu/

IPCC Summary for Policy Makers

An increasing body of observations gives a collective picture of a warming world and other changes in the climate system

Emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate

IPCC Summary for Policy Makers, cont’d

There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities

Anthropogenic climate change will persist for many centuries

http://www.grida.no/climate/vital/37.htm

For the Midwest Warming will be greater for winter than summer Warming will be greater at night than during the

day A 3oF rise in summer daytime temperature triples

the probability of a heat wave Growing season will be longer (8-9 days longer

now than in 1950) More precipitation Likely more soil moisture in summer More rain will come in intense rainfall events Higher stream flow, more flooding


Climate Surprises

Breakdown of the ocean thermohaline circulation (Greenland melt water)

Break-off of the West Antarctic Ice Sheet


Areas subjected to Inundation with a 1 m(~3 ft) rise in sea level

Kennedy SpaceCenter

Miami


Global warming is at least as important an issue as gay marriage or the rising cost of Social Security.

And if it is not seriously debated in the general election, it will measure the irresponsibility of the entire political class. This is an issue that cannot, and must not, be ignored any longer.


Global warming is at least as important an issue as gay marriage or the rising cost of Social Security.

And if it is not seriously debated in the general election, it will measure the irresponsibility of the entire political class. This is an issue that cannot, and must not, be ignored any longer.Walter Cronkite12 March 2004

http://www.philly.com/mld/dailytimes/news/opinion/8159334.htm


What Consitutes “Dangerous Anthropogenic Interference with

the Climate System”?

James Hansen, Director of the NASA GoddardInstitute for Space Studies:

* Radiative forcing limit: 1 Watt/ m2

* 1 oC additional rise in global mean temperature

Hansen, Scientific American, March 2004

Mt. Pinatubo (1991)

El Chichon (1982)Agung, 1963

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONSHansen, Scientific American, March 2004


What Can I Do? Conserve energy Adopt a simpler lifestyle:

– “Elegant simplicity”– “Sophisticated modesty”– “Affluence lite”

Sustainable Development:

To meet the needs of the present without compromising the ability of future generations to meet their needs Brundtland Commission (World Commission on Environment and Development)


Summary Climate change is real and we need to be doing

something about it The longer we wait, the fewer our options Regional patterns of warming will be complicated Climate surprises can’t be

discounted We need dialog on what constitutes

“dangerous anthropogenic interference with the climatesystem”


For More Information For peer-reviewed evidence supporting everything you have

seen in this presentation, see my online Global Change course:

http://www.meteor.iastate.edu/gccourse

Contact me directly:

[email protected]

For a copy of this presentation:

http://www.meteor.iastate.edu/faculty/takle/

Global and Regional Climate Change: What on Earth are We Doing?!

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