Earlier this month, while passing a bill that would curtail the authority of the Environmental Protection Agency, House Republicans rejected three amendments stating that global warming is real, poses a threat and is caused by humans.

The vote was strictly along party lines.

“This just shows us how politicized science can become, especially if there’s policy implications,” said Michael Shermer, executive director of the Skeptics Society and a columnist for Scientific American, via telephone.

Rep. Henry Waxman, D-Calif., ranking member of the House Energy and Commerce Committee, offered an amendment reading, “Congress accepts the scientific finding of the Environmental Protection Agency that ‘warming of the climate system is unequivocal, as is now evident from observations in increases of global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.'”

It failed: 20 voted for, 31 against. Every Republican member of the committee voted no.

Taking issue with this amendment, however, requires an extreme form of denial. Even many who argue against mainstream theories of global warming argue that climate change is real – but they say it’s not caused by humans. The relatively conservative Intergovernmental Panel on Climate Change, set up by the UN, took years to put forward a strong conclusion. Still, in its March 2007 report on the subject the IPCC said that there is no question that the earth is becoming warmer.

The IPCC was only slightly less certain about the cause: it said – with just over 90 confidence – that the reason for the increase in the earth’s temperature over the past century is due to human activity.

Speaking about the bill to which the amendments were offered, Rep. Waxman said, “Some Republicans on the committee will argue today that this bill is not a rejection of science, but if they believed in the serious threat posed by climate change, they would have accepted our offer to work together without preconditions to develop a responsible plan for promoting clean energy and reducing carbon emissions.”

Texas Republican Joe Bartan replied to Waxman, saying, “My good friend from California tries to make it clear that the science is settled. I would say it’s not settled.”

Shermer, who was himself a global warming skeptic until being convinced to change course in 2006, said the climate change debate can be broken down into five questions: Is the earth getting warmer? If so, how much warmer? Do humans cause this? What will be the effects? And what should we do about it?

These questions “should in principle be easily answered,” he said, but remain up in the air due to the politics surrounding the questions.

Scientific observation shows that the earth is getting warmer, Shermer said, and “there are pretty good arguments that it’s human caused, though we have to recognize there are natural cycles.”

There is room for skepticism as to how much warmer, Shermer said. “The margin of error tends to widen the further you go out” in time. Also, no one can be sure exactly what the effects of climate change will be. “It’s not just global warming. It’s climate change. Some places will get better; some will get worse.”

The term “global warming” is based on the average recorded temperature of the earth, which has been going up for years. This warming of the globe leads to climate change, which doesn’t necessarily mean all areas will become warmer. Due to the highly variable and interdependent nature of the world’s weather patterns, warming in some areas could lead to, for example, much colder winters in others.

What should be done, Shermer said, is “off the page of science and purely into the page of politics, of policy decisions.”

“I think we should be cautious about bankrupting ourselves over something that may not be as bad as we think. It’s worth paying close attention to, planning for, making changes. A lot of the suggested changes are good anyway, such as the suggestion to rely on renewable energy,” Shermer concluded.

Opinions of people like Shermer are particularly important to the debate. Very few would be able to call them alarmist. And, say environmentalists, if someone like Shermer could be won over, the science is extremely compelling.

Photo: man trying a way out of flooded residence, Nowshera & Chasd Districts, Pakistan. Copyright © UN-HABITAT