PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Global Climate Change: Science and Consequences Eugene S. Takle Agronomy Department Geological and

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

Global Climate Change:Science and Consequences

Eugene S. TakleAgronomy Department

Geological and Atmospheric Science Department

Iowa State University

Ames, Iowa 50011

[email protected]

Energy Awareness Group Ames Public Library, 7 September 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? Hurricane Katrina

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)


QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.



http://www.earth-policy.org/Indicators/CO2/2004.htm


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


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






Tropical Weather

Weather Underground: http://www.wunderground.com/tropical/

Saffir/Simpson Hurricane Scale CAT Winds & Effects Surge 1 74-95 mph 4-5 ft

No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Also, some coastal flooding and minor pier damage.

2 96-110 mph 6-8 ft Some roofing material, door, and window damage. Considerable damage to vegetation, mobile homes, etc. Flooding damages piers and small craft may break their moorings.

3 111-130 mph 9-12 ft Some structural damage to small residences and utility buildings, with a minor amount of curtainwall failures. Mobile homes are destroyed. Flooding near the coast destroys smaller structures, with larger structures damaged by floating debris. Terrain flooding inland.

4 131-155 mph 13-18 ft More extensive curtainwall failures with some complete roof structure failure on small residences. Major erosion of beach areas. Terrain may be flooded well inland.

5 155 mph+ 18 ft + Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. Flooding causes major damage to lower floors of all structures near the shoreline. Massive evacuation of residential areas may be required.

US Army Corps of Engineers

http://www.sas.usace.army.mil/em/emhurcatinfo.htm

Category 5 Winds greater than 155 mph Shrubs and trees down; considerable damage to roofing; all signs down. Severe and extensive damage to windows and doors Complete roof collapse Destruction of glass in windows and doorsSome complete building failures Small buildings overturned or blown awayComplete destruction of mobile homes Storm surge higher than 18 feet above normal Major damage to lower floors of all structures less than 15 feet above sea level within 500 yards of shore Low lying escape routes inland cut off by rising water three to five hours before hurricane center arrives Massive evacuation of residential areas on low ground within five to 10 miles of shore possibly required

Katrina: Category 5, Winds > 175 mph, Storm surge > 25 ftCatastrophic Hurricanes: Category 3 or larger


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”

More intense hurricanes can be expected in the future due to global warming


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/

Documents

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Global Climate Change: Science and Consequences Eugene S. Takle Agronomy Department Geological and