Romney makes new shift in global warming position

By Michael Levenson, Globe Staff

Is Mitt Romney tweaking his position on global warming?

The former Massachusetts governor had been one of the few Republican presidential candidates to embrace the scientific consensus that human activity contributes to climate change. But in a speech in Pittsburgh on Thursday, he sounded like more of a skeptic.

“My view is that we don’t know what’s causing climate change on this planet,” Romney said in the speech, a clip of which was posted by the liberal blog Think Progress. “And the idea of spending trillions and trillions of dollars to try to reduce CO2 emissions is not the right course for us.”

Romney gave a different answer in June, when he was asked whether humans contribute to climate change.

“I don’t speak for the scientific community, of course,” Romney said at a town-hall meeting in New Hampshire. “But I believe the world’s getting warmer. I can’t prove that, but I believe based on what I read that the world is getting warmer. And number two, I believe that humans contribute to that.”

Today, a top aide to Governor Rick Perry of Texas, a Romney rival and avowed global warming skeptic, accused Romney of flip-flopping on the issue.

“Mitt Romney’s positions change, often dramatically, depending on the audience or location,” Perry spokesman Ray Sullivan said in a statement. “Voters need to consider the fact that Romney, in one week, changed positions on manmade global warming, capping carbon emissions, and Ohio’s efforts to curb union powers.”

Andrea Saul, a Romney spokeswoman, rejected the flip-flopping charge.

“This is ridiculous,” she said in a statement. “Governor Romney’s view on climate change has not changed. He believes it’s occurring, and that human activity contributes to it, but he doesn’t know to what extent. He opposes cap and trade, and he refused to sign such a plan when he was governor. Maybe the bigger threat is all the hot air coming from career politicians who are desperate to hold on to power.”

Romney has sometimes been hard to pin down on the issue.

He wrote in his 2010 book “No Apology,” “I believe that climate change is occurring…I also believe that human activity is a contributing factor. I am uncertain how much of the warming, however, is attributable to man and how much is attributable to factors out of our control.”

In New Hampshire, in August, he said: “I think the earth is getting warmer…I think humans contribute to that. I don’t know by how much. It could be a little. It could be a lot.”

Several of Romney’s rivals for the GOP nomination are global warming skeptics, taking a stance that appeals to some conservative voters who also question the science of climate change.

“I’m a skeptic about that, and I’m not afraid to say I’m a skeptic about that,” Perry said last month in New Hampshire. “Why would we put our children’s future in jeopardy on science that is, frankly, not proven?”

Despite the candidates’ statements, non-partisan scientists overwhelmingly agree that humans are contributing to climate change.

A 2011 report by an expert committee selected by the National Academy of Sciences found, “Climate change is occurring, is very likely caused primarily by the emission of greenhouse gases from human activities, and poses significant risks for a range of human and natural systems.”

The National Oceanic and Atmospheric Administration found in 2009 that “the scientific evidence that our world is warming is unmistakable.”

The US Global Change Research Program, a program started by Congress in 1990 to coordinate federal research on the global environment, found in 2009, “Observations show that warming of the climate is unequivocal. The global warming observed over the past 50 years is due primarily to human-induced emissions of heat-trapping gases.”