Iowa’s Climate 2030

Eugene S. TakleDirector, Climate Science ProgramProfessor of Atmospheric Science

Department of Geological and Atmospheric SciencesProfessor of Agricultural Meteorology

Department of AgronomyIowa State University

Ames, Iowa 50011gstakle@iastate.edu

Municipal Utilities 2030Ankeny, Iowa 8 April 2010

“I hear so many conflicting views on

climate change, I don’t know what or

who to believe”Soybean producer from NE Iowa

In science, the prevailing theory is the one that explains the balance of evidence

What is the evidence?

http://www.ncdc.noaa.gov/img/climate/research/2008/ann/global-jan-dec-error-bar-pg.gif

Global Mean Surface Temperature

http://www.ncdc.noaa.gov/img/climate/research/2008/ann/global-jan-dec-error-bar-pg.gif

Global Mean Surface Temperature

http://www.ncdc.noaa.gov/img/climate/research/2008/ann/global-jan-dec-error-bar-pg.gif

Global Mean Surface Temperature

http://data.giss.nasa.gov/gistemp/graphs/

NASA

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

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

Temperature Trends in Upper and Lower Atmosphere

Upper Atmosphere

(Stratosphere)

Lower Atmosphere

(Troposphere)

“One of the clearest trends in the United States observational record is an increasing frequency and intensity of heavy precipitation events… Over the last century there was a 50% increase in the frequency of days with precipitation over 101.6 mm (four inches) in the upper midwestern U.S.; this trend is statistically significant “

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.

Arctic Sea-Ice Decline

Decline in Greenland Ice Mass

Equivalent to about 5 ft of ice over the state of Iowa each year

Emanual, Kerry, 2005: Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436, 686-688.

Sea-surface temperature

V V

Tropical Atlantic OceanHurricane Power Dissipation Index (PDI)

V

Ocean Heat Content

1oC rise in top 3 m of global ocean is equivalent to a 1oC rise in entire atmosphere

Where is this extra heat coming from?Possible mechanisms:• More solar radiation• Less reflection from clouds• Less reflection from Earth’s

surface• More energy trapped and recycled by ozone and greenhouse gases

Earth’s Energy Balance:

Incoming solar = outgoing infrared radiation

But rapid changes in atmosphere and ocean temperatures and loss of land and sea ice indicate an imbalance

Earth’s Energy Balance:

Incoming solar = outgoing infrared radiation

But rapid changes in atmosphere and ocean temperatures and loss of land and sea ice indicate an imbalance

?

?

? ?

*Other solar cycles have periods of 22,000, 41,000, and 100,000 years with 0.1% variation.

0.1%

Forcing Factors in the Global Climate

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.

More trapped (recycled) heat

More cloud & land reflection

See Arritt for details this afternoon

Increased Greenhouse Increased Greenhouse Gases => Global HeatingGases => Global Heating

Increasing Increasing greenhouse gases greenhouse gases increases heating increases heating of the Earthof the Earth

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009.

Global Carbon Emissions (Gt)

Actual emissions are exceeding worst case scenarios projected in 1990

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.

Warming of the Lower and Upper Atmosphere Produced by Natural and Human Causes

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.

Warming of the Lower and Upper Atmosphere Produced by Natural and Human Causes

Note that greenhouse gases have a unique temperature signature, with strong warming in the upper troposphere, cooling in the lower stratosphere and strong warming over the North Pole. No other warming factors have this signature.

http://www.ncdc.noaa.gov/img/climate/research/2008/ann/global-jan-dec-error-bar-pg.gif

Global Mean Surface Temperature

Attribution studies: See Anderson this afternoon for applications to the Midwest

Source: Jerry Meehl, National Center for Atmospheric Research

The balance of evidence for the magnitude and distribution of warming is explained by increases in atmospheric greenhouse gases

The “Cone of Uncertainty”

IPCC Fourth Assessment Report Summary for Policy Makers

Balanced fuel sourcesEnergy intensive

More environmentally friendly

If current emission trends continue, global temperature rise will exceed worst case scenarios projected in 2007

FI =fossil intensive

IPCC 2007

December-January-February Temperature Change

A1B Emission Scenario2080-2099 minus1980-1999

7.2oF

6.3oF

IPCC 2007

June-July-August Temperature Change

A1B Emission Scenario2080-2099 minus1980-1999

4.5oF

5.4oF

June-July-August Temperature Change

A1B Emission Scenario2080-2099 minus1980-1999

4.5oF

5.4oF

Not the direction of current trends

IPCC 2007

IPCC 2007

Low confidence in model projection of summer precipitation

IPCC 2007

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.

Low confidence

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.

Trend of increase in occurrence of heavy precipitation over the 20th C is consistent with increasing GHG concentrations.

Frequency of intense precipitation events is likely to increase in the future.

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.

MitigationPossible

AdaptationNecessary

AdaptationNecessary

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

Karl, T. R., J. M. Melillo, and T. C. Peterson, (eds.), 2009: Global Climate Change Impacts in the United States. Cambridge University Press, 2009, 196pp.

AdaptationNecessary

AdaptationNecessary

MitigationPossible

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

Adapted from Folland et al. [2001]

Observed Summer (JJA) Daily Maximum Temperature Changes (K), 1976-2000

Des Moines Airport Data

1983: 13

1988: 10

2009: 0

Des Moines Airport Data

1983: 13

1988: 10

2009: 0

6 days ≥ 100oF in the last 20 years

State-Wide Average Data

State-Wide Average Data

Totals above 40”

Cedar Rapids Data

Cedar Rapids Data

D. Herzmann, Iowa Environmental Mesonet

State-Wide Average Data

Projected Changes* for the Climate of the Midwest

Temperature

*Estimated from IPCC reports

*Estimated from IPCC reports

Projected Changes* for the Climate of the Midwest

Precipitation

Iowa Agricultural Producers’ Adaptations to Climate Change

Longer growing season: plant earlier, plant longer season hybrids, harvest later

Wetter springs: larger machinery enables planting in smaller weather windows

More summer precipitation: higher planting densities for higher yields

Wetter springs and summers: more subsurface drainage tile is being installed, closer spacing, sloped surfaces

Fewer extreme heat events: higher planting densities, fewer pollination failures

Higher humidity: more spraying for pathogens favored by moist conditions. more problems with fall crop dry-down, wider bean heads for faster harvest due to shorter harvest period during the daytime.

Drier autumns: delay harvest to take advantage of natural dry-down conditions

HIGHER YIELDS!!Is it genetics or climate? Likely

some of each.

Wind Power: A New Energy

Opportunity for Iowa

54-hour Forecasts Initialized at 00UTC (6 PM CST)

Different turbulence schemes

Observations at Pomeroy, IA

Global model initialization

Midnight Noon Midnight MidnightNoon

Conceptual Model of Turbine-crop Interaction via Mean Wind and Turbulence

Fields

__ ___________________________________

Speed recovery

CO2H2O

Heat

day

night

Summary There is no scientifically defensible explanation for

atmospheric warming, increase in ocean heat content, and loss of ocean and land ice over the last 40 year other than increase of anthropogenic greenhouse gases

Some recent climate trends in the Midwest that have been favorable to agriculture likely will continue in the next few years

Climate challenges to agriculture will intensify toward mid-century

Iowa’s wind energy resources offer an alternative for contributing to the nation’s energy needs while reducing emissions of greenhouse gases

For More Information National academies of science joint statement (May 2009):

G8+5 Academies’ joint statement: Climate change and the transformation of energy technologies for a low carbon future. [http://www.nationalacademies.org/includes/G8+5energy-climate09.pdf]

North American Regional Climate Change Assessment Program: http://www.narccap.ucar.edu/

For current activities on the ISU campus, regionally and nationally relating to climate change see the Climate Science Initiative website: http://climate.agron.iastate.edu/

Contact me directly: gstakle@iastate.edu