Global Environmental Changes: Technology and the Future of Planet Earth Eugene S. Takle, PhD, CCM Professor of Atmospheric Science Professor of Agricultural Meteorology Iowa State University Ames, Iowa 50011 gstakle@iastate.edu College for Seniors, 10 April 2006

Outline Changes in atmospheric carbon dioxide Radiative forcing Simulations of global climate and future climate change “Dangerous anthropogenic inter- ference with the climate system”? “Climate surprises” Summary

Carbon Dioxide and Temperature

Carbon Dioxide and Temperature 2006

Carbon Dioxide and Temperature 2040 2006

Carbon Dioxide and Temperature Stabilization at 550 ppm

Carbon Dioxide and Temperature “Business as Usual” (fossil intensive) 2100

“Nobody believes that the US economy can still be petroleum based in 2050, yet there is no national plan” Mark Kushner, Dean Iowa State University College of Engineering President’s Council Meeting 13 January 2006

El Chichon (1982) Agung, 1963 Mt. Pinatubo (1991) Hansen, Scientific American, March 2004

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

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

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

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)

Tropical Atlantic Ocean Hurricane Power Dissipation Index (PDI) Sea-surface temperature V V V Emanual, Kerry, 2005: Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436, 686-688.

Tropical Atlantic Ocean Hurricane Power Dissipation Index (PDI) Sea-surface temperature V V V Emanual, Kerry, 2005: Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436, 686-688.

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

http://en.wikipedia.org/wiki/Image:Katrina_vs_sea_surface_height.JPG

Source: Jerry Meehl, National Center for Atmospheric Research From Jerry Meehl This slide shows the time evolution of globally averaged surface air temperature from multiple ensemble simulations of 20th century climate from the NCAR Parallel Climate Model (PCM) compared to observations. The simulations start in the late 19th century, and continue to the year 2000. The temperature scale at left is in degrees Centigrade, and temperature anomalies are calculated relative to a reference period averaged from 1890 to 1919. The black line shows the observed data, or the actual, recorded globally averaged surface air temperatures from the past century. The blue and red lines are the average of four simulations each from the computer model. The pink and light blue shaded areas depict the range of the four simulations for each experiment, giving an idea of the uncertainty of a given realization of 20th century climate from the climate model. The blue line shows the average from the four member ensemble of the simulated time evolution of globally average surface air temperature when only "natural" influences (solar variability and volcanic eruptions) are included in the model. Therefore, the blue line represents what the model says global average temperatures would have been if there had been no human influences. The red line shows the average of the four member ensemble experiment when natural forcings AND anthropogenic influences (greenhouse gases including carbon dioxide, sulfate aerosols from air pollution, and ozone changes) are included in the model. Note that this model can reproduce the actual, observed data very well only if the combined effects of natural and anthropogenic factors are included. The conclusion that can be drawn is that naturally occuring influences on climate contributed to most of the warming that occurred before WWII, but that the large observed temperature increases since the 1970s can only be simulated in the model if anthropogenic factors are included. This confirms the conclusion of the IPCC Third Assessment Report that most of the warming we have observed in the latter part of the 20th century has been due to human influences. Source: Jerry Meehl, National Center for Atmospheric Research

Source: Jerry Meehl, National Center for Atmospheric Research From Jerry Meehl This slide shows the time evolution of globally averaged surface air temperature from multiple ensemble simulations of 20th century climate from the NCAR Parallel Climate Model (PCM) compared to observations. The simulations start in the late 19th century, and continue to the year 2000. The temperature scale at left is in degrees Centigrade, and temperature anomalies are calculated relative to a reference period averaged from 1890 to 1919. The black line shows the observed data, or the actual, recorded globally averaged surface air temperatures from the past century. The blue and red lines are the average of four simulations each from the computer model. The pink and light blue shaded areas depict the range of the four simulations for each experiment, giving an idea of the uncertainty of a given realization of 20th century climate from the climate model. The blue line shows the average from the four member ensemble of the simulated time evolution of globally average surface air temperature when only "natural" influences (solar variability and volcanic eruptions) are included in the model. Therefore, the blue line represents what the model says global average temperatures would have been if there had been no human influences. The red line shows the average of the four member ensemble experiment when natural forcings AND anthropogenic influences (greenhouse gases including carbon dioxide, sulfate aerosols from air pollution, and ozone changes) are included in the model. Note that this model can reproduce the actual, observed data very well only if the combined effects of natural and anthropogenic factors are included. The conclusion that can be drawn is that naturally occuring influences on climate contributed to most of the warming that occurred before WWII, but that the large observed temperature increases since the 1970s can only be simulated in the model if anthropogenic factors are included. This confirms the conclusion of the IPCC Third Assessment Report that most of the warming we have observed in the latter part of the 20th century has been due to human influences. Source: Jerry Meehl, National Center for Atmospheric Research

Source: Jerry Meehl, National Center for Atmospheric Research From Jerry Meehl This slide shows the time evolution of globally averaged surface air temperature from multiple ensemble simulations of 20th century climate from the NCAR Parallel Climate Model (PCM) compared to observations. The simulations start in the late 19th century, and continue to the year 2000. The temperature scale at left is in degrees Centigrade, and temperature anomalies are calculated relative to a reference period averaged from 1890 to 1919. The black line shows the observed data, or the actual, recorded globally averaged surface air temperatures from the past century. The blue and red lines are the average of four simulations each from the computer model. The pink and light blue shaded areas depict the range of the four simulations for each experiment, giving an idea of the uncertainty of a given realization of 20th century climate from the climate model. The blue line shows the average from the four member ensemble of the simulated time evolution of globally average surface air temperature when only "natural" influences (solar variability and volcanic eruptions) are included in the model. Therefore, the blue line represents what the model says global average temperatures would have been if there had been no human influences. The red line shows the average of the four member ensemble experiment when natural forcings AND anthropogenic influences (greenhouse gases including carbon dioxide, sulfate aerosols from air pollution, and ozone changes) are included in the model. Note that this model can reproduce the actual, observed data very well only if the combined effects of natural and anthropogenic factors are included. The conclusion that can be drawn is that naturally occuring influences on climate contributed to most of the warming that occurred before WWII, but that the large observed temperature increases since the 1970s can only be simulated in the model if anthropogenic factors are included. This confirms the conclusion of the IPCC Third Assessment Report that most of the warming we have observed in the latter part of the 20th century has been due to human influences. Source: Jerry Meehl, National Center for Atmospheric Research

Source: National Center for Atmospheric Research

The planet is committed to a warming over the next 50 years regardless of political decisions Source: National Center for Atmospheric Research

The planet is committed to a warming over the next 50 years regardless of political decisions Mitigation Possible Adaptation Necessary Source: National Center for Atmospheric Research

Source: Intergovernmental Panel on Climate Change, 2001 Report

40% Probability 5% Probability Source: Intergovernmental Panel on Climate Change, 2001 Report

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).

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

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

What Constitutes “Dangerous Anthropogenic Interference with the Climate System”? James Hansen, Director of the NASA Goddard Institute for Space Studies: * Radiative forcing limit: 1 Watt/ m2 * 1 oC additional rise in global mean temperature

El Chichon (1982) Agung, 1963 Mt. Pinatubo (1991) Hansen, Scientific American, March 2004

El Chichon (1982) Agung, 1963 Mt. Pinatubo (1991) Imbalance = 1 Watt/m2 in 2018 Hansen, Scientific American, March 2004

Hansen, Scientific American, March 2004

Impact of a 1-m rise in sea level on low-lying areas Kennedy Space Center Impact of a 1-m rise in sea level on low-lying areas Projected sea-level rise In 21st century: 0.5 to 1.0 m Areas subjected to Inundation with a 1 m (~3 ft) rise in sea level Miami Source: Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment (www.acia.uaf.edu) Cambridge University Press (www.cambridge.org).

North America Regional Climate Change Assessment Program Linda O. Mearns, National Center for Atmospheric Research Principal Investigator Raymond Arritt, William Gutowski, Gene Takle, Iowa State University Erasmo Buono, Richard Jones, Hadley Centre, UK Daniel Caya, OURANOS, Canada Phil Duffy, Lawrence Livermore National Laboratories, USA Filippo Giorgi, Jeremy Pal, Abdus Salam ICTP, Italy Isaac Held, Ron Stouffer, NOAA Geophysical Fluid Dynamics Laboratory, USA René Laprise, Univ. de Québec à Montréal, Canada Ruby Leung, Pacific Northwest National Laboratories, USA Linda O. Mearns, Doug Nychka, Phil Rasch, Tom Wigley, National Center for Atmospheric Research, USA Ana Nunes, John Roads, Scripps Institution of Oceanography, USA Steve Sain, Univ. of Colorado at Denver, USA Lisa Sloan, Mark Snyder, Univ. of California at Santa Cruz, USA http://www.narccap.ucar.edu/

NARCCAP Plan A2 Emissions Scenario GFDL CCSM HADAM3 CGCM3 MM5 RegCM3 link to EU programs CGCM3 1960-1990 current 2040-2070 future Provide boundary conditions MM5 Iowa State/ PNNL RegCM3 UC Santa Cruz ICTP CRCM Quebec, Ouranos HADRM3 Hadley Centre RSM Scripps WRF NCAR/ Note: AGCM time slices to be included, too. Initial phase involves driving RCMs with reanalysis output. Reanalyzed climate , 1979-2000

Climate Model Resolution global regional (land) regional (water) Only every second RCM grid point is shown in each direction

Application of Climate Change Scenarios Crop pathogens Habitat/climate for invasive species Soil or aquatic ecosystems Hardiness zones for trees Freshwater availability Lake-level changes Recreation changes Space-heating/power demands Crop yields Soil carbon levels Soil erosion Bird migration patterns Dairy cow milk production Heat stress in beef cattle Snowpack/reservoir performance

Summary Climate change is real and we need to be doing something about it to prevent “dangerous anthropogenic interference with the climate system” Mitigation will have no effect for 50 years, so we need to develop adaptation strategies for the short term The longer we wait, the fewer our options Regional patterns of warming will be complicated Climate surprises can’t be discounted We need dialog between scientists and the private sector to develop both adaptation and mitigation strategies

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: gstakle@iastate.edu