Says human impact based on uncertain science
University of Delaware scientist and state climatologist Dr. David Legates believes that the earth is warming. He believes to a certain extent that humans are having an impact. But his underlying belief is this: the amount of impact humans are having on a warming phenomenon is questionable at best.
“Skeptics believe there has been non-change and humans play no role,” said Legates, the director of the university’s Center for Climatic Research. “That is a misrepresentation. I think climate has changed. The temperature has been rising for the last 400 years. I don’t think humans have nearly as much influence (as has been predicted).”
His claim challenges a groundbreaking finding in the Intergovernmental Panel on Climate Change Feb. 2 global warming report that stated with roughly 90 percent certainty that humans were to blame for global warming for polluting the earth with greenhouse gases.
Greenhouse gases, such as CO2 — the most heavily emitted of those gases through energy production in this country — trap heat inside the atmosphere. The phenomenon is necessary to provide an inhabitable earth but an excess in greenhouse gases creates changes in climate, which can be disastrous, many have predicted.
The IPCC, a United Nations-formed group of scientists from more than 100 countries, predicted on Feb. 2 that sea levels will rise 7 to 23 inches in the next century because of warming. Average global temperatures will rise 2 to 12 degrees in the same period, the report stated, with the likelihood of more intense storms. Some 600 scientists from 40 countries authored the report.
A statement released by the American Association for the Advancement of Science, a non-profit that serves 262 science societies and academies worldwide, on Feb. 18 supported the IPCC findings.
“The scientific evidence is clear: global climate change caused by human activities is occurring now, and it is a growing threat to society,” the statement reads.
Even the University of Delaware, Legates’ own school, jumped into the debate on the side of the IPCC. Its Feb. 3 report, co-authored by Dr. Willett Kempton — who said that the IPCC did not go far enough — explored potential impacts of warming 300 to 1000 years from now, revealing dire consequences for the state in the face of inaction.
Action to curb emissions from CO2 and other harmful pollutants is needed to divert dramatic climate change, loss of land and life, scientists there and elsewhere have said. Delaware is currently a member of the Regional Greenhouse Gas Initiative, a regional state-led cooperative to fight CO2 emissions.
Legates’ position: the science is questionable, and approving regulations based on questionable science is irresponsible.
“You can have a range of views,” said Kempton, an associate professor and senior policy scientist at the university. “Generally, you want to have different views represented. Some in the University and outside the University would say that Dave is enough outside of the range that he is not really contributing to the discussion. But that’s a matter of opinion, too.”
Legates was one of eight authors of a brief filed in the Supreme Court last year, questioning claims that carbon dioxide emissions are harmful and should be regulated. A group of 11 states, with Massachusetts as the lead petitioner, appealed to the court an Environmental Protection Agency decision not to regulate carbon dioxide emissions.
An attorney for the agency argued in the Supreme Court on Nov. 29 that the EPA did not have the authority to “embark on the regulation of greenhouse gas emissions to address global warming” and cited the “scientific uncertainty” surrounding the phenomenon.
Legates and the other scientists addressed that uncertainty in their brief.
“There is insufficient evidence that carbon dioxide emissions will endanger public health or welfare,” the brief stated. “The net affects of increasing carbon dioxide emissions are not known.”
Again: questionable science, Legates argued. Legates said that he worries fear of potential consequences of warming will lead to regulations based on this unproven science. Regulations or taxes could drive prices up and stress budgets nationwide. And since humans are natural carbon dioxide emitters, regulating the gas — even labeling it a harmful pollutant — can be a bit tricky, Legates added.
“I think there are some prudent things we can do. (Emission reductions) would have an impact even if humans weren’t having any of an impact (on warming),” Legates said, adding that reducing U.S. reliance on foreign oil would be reason enough to regulate. “The debate is still uncertain on exactly how much humans have an impact”