President Barack Obama says he will urge the U.S. Senate to pass climate change legislation when it returns from a break next week. But the politics involving this issue is still evident at all levels of government, including among Maine's gubernatorial candidates. All but one of the seven Republican candidates decline to embrace the science behind climate change. And that surprises and disappoints science professors at Maine's colleges and universities.

In a recent MPBN debate, all seven of the Republican candidates for governor were asked this question by host Jennifer Rooks: "Do you believe global warming is in large part caused by human activities?"

"I have absolutely no idea, but I do think it's important that we conserve our resources and use them as prudently as possible," responded Steve Abbott.

Neither Abbott, whose former boss, U.S. Senator Susan Collins, is a co-sponsor of climate change legislation, nor Les Otten who runs an alternative energy company, nor former Husson University President William Beardsley, said that they believe climate change is in part man made.

In fact, Beardsley challenged the science outright. "I believe we should be focusing on our economy rather than chasing after issues that haven't been proven in science," he said.

And Bruce Poliquin, who studied economics at Harvard, questioned it. "Clearly our climate is changing; the question is, is man responsible for that climate change? I personally am suspect."

Only one of the Republican gubernatorial candidates, state Senator Peter Mills, answered in the affirmative. "I think most scientists agree that it is -- a large component of it is man-caused."

"Eveybody I know here at Colby in the Science division and the Environmental Studies Program certainly have strong confidence that climate change is happening and that humans have a significant role in climate warming," says Dr. Philip Nyhus, an assistant professor of environmental studies at Colby.

Nyhus says he's disappointed that, with the exception of Peter Mills, Maine's Republican gubernatorial candidates don't take a stronger position on global warming or embrace science simply because they might consider it politically unpopular.

A recent national poll finds 40 percent of likely U.S. voters think climate change is caused by human activity. But 44 percent think long-term planetary trends are responsible. Five percent blame something else. And ten percent say they just don't know.

Phil Camill is a global change ecologist and bio-geochemist at Bowdoin College who has studied arctic climate impacts and permafrost thaw. "When somebody asks the question: Is climate warming human-caused or natural, the correct answer is 'yes.' It's actually both."

How do they know? Camill says scientists have studied global warming over the last two centuries and figured out how much of it is due to natural factors, such as changes in solar radiation and volcanos, versus human-caused factors, such as emitting greenhouse gases in the atmosphere.

What they find is that there's been about a point-nine degree centigrade warming since about 1880. But Camill says two-thirds of the warming that's occurred over the last 120 years has been caused mainly by greenhouse gases. "To put this another way: There's no way you can explain the modern warming that we're experiencing only with natural factors. The only thing that accounts for that are greenhouse gases."

In an email, Dr. Mark Green of St. Joseph's College says it's baffling to him that climate change has become a political question when society -- and policy makers -- rely on scientists for so many things, often accepting their results with little or no question. Green studies ocean acidification as a result of carbon emissions.

For the record, all four of Maine's Democratic gubernatorial candidates are on board with the scientist. But Green wonders what it is about climate change that causes many in the GOP to question the validity of the scientific consensus that global warming is real and is being caused by human actions.

"I would hope we could do a better job of making it clear," says David Hales, president of the College of the Atlantic in Bar Harbor, where he says most of his faculty probably support the idea that climate change is, in part, human caused. COA is one of more than 800 colleges and universities, including more than half a dozen in Maine, that have signed onto the president's Climate Commitment, "which has as its basic premise that human behavior has caused the crisis that we're seeing," Hales says.

Not only educational institutions, but national and international scientific organizations that rely on peer-reviewed research all say the same thing. They follow the 2001 position of the Intergovernmental Panel on Climate Change that states in part: "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities."

In fact, with the exception of a group of petroleum geologists in 2007, not one scientific body of national or international standing has taken an opposing stance in the past nine years.