Newswise — Evidence about ancient climates shows that Earth has undergone many natural climate cycles throughout its long history. But now human activities have added a new variable to the climate system. The rapid rise of heat-trapping carbon dioxide due to the combustion of fossil fuels is having a dramatic impact. Ice core data reveal that atmospheric CO2 is now 30 percent higher than any time in the last 800,000 years. If humanity wishes to preserve a planet similar to that on which civilization developed, CO2 must be reduced to below the present atmospheric amount.

So says Dr. James Hansen, Director of NASA's Goddard Institute for Space Studies, and one of the world's leading authorities on present-day climate change. Hansen will speak on Tuesday, 7 October, from noon to 1:15 p.m., as part of a slate of activities planned in recognition of the International Year of Planet Earth:

Hansen's message, titled "Target Atmospheric CO2: Where Should Humanity Aim?" will be presented to scientists gathering in Houston, Texas, USA, on 5-9 October for the 2008 Joint Annual Meeting of the Geological Society of America (GSA), Soil Science Society of America (SSSA), American Society of Agronomy (ASA), and Crop Science Society of America (CSSA), the Gulf Coast Association of Geological Societies (GCAGS) with the Gulf Coast Section SEPM, and hosted by the Houston Geological Society (HGS).

Hansen's lecture will be broadcast live online (CST) at

Two complimentary technical sessions will surround Hansen's presentation—one on Tuesday morning and one in the afternoon, titled, "Global Warming Science: Implications for Geoscientists, Educators, and Policy Makers I & II" Twenty-two speakers, leaders in their respective fields, will to expand the climate change discussion on a variety of topics.

"The goal of these two sessions is to review current hard science on global warming, its current and projected impacts, and policy implications for mitigation and adaptation," says Andrew Buddington, session co-convener and geology teacher at Spokane Community College. "We recognize the importance of the overall subject, and the topical line-up is impressive."

View all morning session abstracts: Session number 228 (8:00-11:30 a.m.)

View all afternoon session abstracts: Session number 264 (1:30-5:00 p.m.)


Michael Mann, Dept. of Meteorology and Earth and Environmental Systems Institute, Penn State University, will present recent studies on temperature rise predictions."Global Climate Change: The Science, the Likely Impacts, and Possible Solutions" (8:10 a.m.)

George Luber, National Center for Environmental Health, Centers for Disease Control and Prevention, will review the spectrum of public health activities appropriate to addressing climate change."Climate Change and Human Health: The Public Health Response" (9:20 a.m.)

Gifford Miller, INSTAAR and Geological Sciences, University of Colorado at Boulder, will address decreasing uncertainty of the future consequences of climate change for modern society."The Arctic Bellweather Is Ringing!: Paleoclimate Data Quantify the Magnitude of Past Arctic Amplification" (10:20 a.m.) Vladimir Romanovsky, Geophysical Institute of the University of Alaska, will discuss possible ramifications of permafrost degradation."Past, Present, and Future of Permafrost in a Changing World" (2:25 PM)

Camille Parmesan, University of Texas at Austin, examines biodiversity changes in the context of global warming. A temperature rise of 2 degrees Celsius over the next 100 years may result in massive species extinctions and possibly loss of some natural systems altogether."Impacts of Climate Change on Biodiversity and Human Health" (3:25 p.m.)

David Bush, University of West Georgia, says that decades of coastal studies and an increasing focus on planning has not checked the global trend of coastal-zone population growth and development, and coastal planners/managers cannot wait for the answer to the causes of global warming to make decisions regarding land-use plans and regulations."Sea Level Is Risen. Storms Are a Certainty. Now What?" (4:10 p.m.)

Numerous other sessions and papers at the Houston Joint Meeting address issues surrounding global climate change. The complete technical program is online and fully searchable (by date, author, program, or keyword) at:


Lecture by Dr. James Hansen, Director, NASA's Goddard Institute for Space Studies"Target Atmospheric CO2: Where Should Humanity Aim?" Tuesday, 7 October 2008, noon to 1:15 p.m.George R. Brown Convention Center, General Assembly Theater B

"Global Warming Science: Implications for Geoscientists, Educators, and Policy Makers I & II" Tuesday, 7 October 2008, 8:00"11:30 a.m. and 1:30"5:00 p.m.George R. Brown Convention Center, General Assembly Theater B

For more information on the 2008 Joint Meeting visit