Published on Wednesday, July 30, 2003 by the Environment News Service
GOP Senators Blame Nature for Climate Change
by J.R. Pegg
WASHINGTON - Some Senate Republicans say there is considerable doubt that the climate is warming and if it is, humans are not responsible. Backing up statements he made on the Senate floor Monday, Oklahoma Senator James Inhofe today told colleagues of the Senate Environment and Public Works Committee that the science shows natural variability, not human activity, is the "overwhelming factor" influencing climate change.
Inhofe cited findings of a study by Drs. Willie Soon and Sallie Baliunas of the Harvard-Smithsonian Center for Astrophysics that determined the 20th century was neither the warmest nor the century with the most extreme weather within the past millennium.
But a climate expert at today's hearing told Inhofe that the mainstream climate research community believes the Soon and Baliunas study is "nonsense."
The study is "fundamentally unsound," testified Michael Mann, University of Virginia environmental sciences professor and a lead author of the United Nation's Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report.
Natural variability is a large factor in climate change, Mann said, but it can not explain the warming of the past two decades.
There is no doubt that "mainstream climate researchers" have concluded that the warming in the late 20th century is "unprecedented in a very long term context and that this warmth is likely related to the activity of human beings," Mann told the committee.
Today's hearing illustrated the contentious debate over climate change in American politics, as the Bush administration and some in Congress contend that the science is too uncertain for the government to force industry to reduce greenhouse gas emissions, in particular carbon dioxide (C02).
For many there appears overwhelming evidence - from the United Nations, the U.S. government and independent researchers across the globe - that human activities, in particular the burning of fossil fuels, is impacting the climate.
The IPCC panel, for example, says that atmospheric concentrations of CO2 have increased to a level higher than at any time during the last 420,000 years.
Mann said today that new evidence indicates these levels have not been seen for some 10 million to 20 million years, since the time of the dinosaurs. Many scientists predict that the average global temperature could rise from one to four degrees Fahrenheit by 2050 and some say it could rise as much as 10.4 degrees Fahrenheit over the next 100 years.
Critics believe the administration and its Congressional allies are casting doubt on the science in order to avoid difficult political choices about how to address the concern.
The Bush administration said last week that it was launching a new initiative to study climate change, amid criticism that it edited a U.S. Environmental Protection Agency report to remove references to global warming.
"I know these debates have political implications because heaven forbid we would tell somebody in the private sector not to do something or that we might have to make sacrifices in the quality of our life for future generations," said Senator Hillary Clinton, a New York Democrat. "But it is not useful to carry out this kind of argumentation when it is clear by the very nature of human development and industrialization we have changed is in the atmosphere, in the Earth and in the waters."
There are several bills before the Senate that would put caps on carbon dioxide emissions and there is a good chance proponents will try to tack amendments with similar intent to the Senate energy bill this week.
These caps would "devastate" the economy, said Inhofe, by increasing energy prices and causing coal-fired plants to switch to natural gas. Inhofe said today's hearing was an attempt to hone in on "sound science" as the Senate considers the implications of climate change.
"It is no secret that we are not scientists up here, so we look at things logically," he said.
Inhofe rejected Mann's analysis and noted that his study, which shows a spike in warming in the late 20th century, came out in 1999, whereas the Soon and Baliunas study came out in 2003.
Mann's research is commonly referred to as the "hockey stick" study, because it shows a relatively stable trend in climate temperatures until a sharp up tick in the past two decades.
This new study "shifts the paradigm away from the previous hockey stick study," Inhofe said.
The latter study finds that natural variability, including land use changes and the output of the Sun, is responsible for any climate change over the past 1,000 years.
"The climate of the 20th century is neither unreasonable nor the most extreme," Soon told the committee.
There was a warming trend from about 800 A.D. to 1300 A.D., he said, then general cooling until 1900 A.D. - a "little ice age."
The Soon and Baliunas study gets beyond the observational biases of much of the climate research to date, said Dr. David Legates, director of Center for Climatic Research at the University of Delaware's Department of Geography.
It has the "inescapable conclusion that climate variability has been a natural occurrence," Legates said.
Mann contends that Soon and Baliunas misuse proxy data reflective of changes in moisture and drought, rather than temperature, and do not distinguish between regional temperature anomalies and hemispheric mean temperature. In addition, Mann says the Harvard Smithsonian scientists did not correctly account for uncertainties and failed to accurately define the modern base period to compare past climate to.
"There is little valid in that paper, they got just about everything wrong," Mann said.
Some media reports, in particular by Cox News Service, have also found the Soon and Baliunas research was underwritten by the American Petroleum Institution - an industry trade association - but Inhofe and others are adamant the study is sound.
"It is easy for me to believe there is a trend of warming, but the bottom line is what is causing it and what are the long term effects," said Colorado Republican Wayne Allard. "I am not sure scientists understand all the variables."Land use, in particular urbanization, clearly must account for some of the warming that scientists say is occurring, he told Mann.
"It seems to be a fundamental concept," Allard said. "From my practical experience it seems to me there is warming effect from pavement. When I walk out on pavement with my bare feet they get burned. If I walk on grass they feel cooler."
"When you are walking, you are only covering a small fraction of the Earth," Mann responded. "The urban heat island effect is overwhelmed by larger scale changes that we do not necessarily see because they are not where we are walking around. Large surface areas of the Earth are being changed in terms of their vegetation characteristics and that has a net cooling effect - that answer is clear in the peer review research."
Allard added that water vapor - not C02 - is not the major greenhouse gas and said that all greenhouse gases should be considered within the debate.
Mann agreed, and said it would be "shortsighted to talk only about C02."
"It is extremely misleading, however, when scientists cite the role of water vapor as a greenhouse gas," Mann explained. "The concentration of water vapor in the atmosphere can not be controlled by us directly. It is fixed by the surface temperature of the Earth."
It is the trace gases - methane, C02, nitrous oxides, and chlorofluorocarbons - that "we can actually control," Mann explained.
How to control these emissions is at the center of the U.S. debate over climate change - the nation contributes more than 25 percent of the world's total greenhouse gas emissions. Supporters of aggressive action say that it is too risky not to act.
"The challenge is not to put our heads in the sand and let the academic argument take place, but figure out how in a sensible and prudent manner we could ameliorate these changes," said Clinton.
Copyright © 2003 Environment News Service (ENS)