While the Obama administration presses forward with plans to deal with climate change, Congress remains steadfast against taking action. It's not easy to find a scientist who will agree with that point of view. But Republicans have found an ally in a climate scientist by the name of Judith Curry.
Curry actually entered the public eye in 2005, with a paper in Science magazine warning that hurricanes were likely to become more intense as a result of climate change. But in the years since then, she's soured on the scientific consensus about climate change. Her mantra now is, "We just don't know."
This message plays well in the House of Representatives, so it's no surprise that Curry was called to testify at a subcommittee hearing there this spring.
Curry certainly has the credentials. She is a professor and chairwoman of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology. She also runs a side business as a private weather forecaster. But she doesn't deny the basic principles of climate change.
"If all other things remain equal, it's clear that adding more carbon dioxide to the atmosphere will warm the planet," she told the committee.
But, she went on, not all things are equal. She says there's so much uncertainty about the role of natural variation in the climate that she doesn't know what's going to happen. She says a catastrophe is possible, but warming could also turn out to be not such a big deal.
And she focuses on uncertainties and unknown unknowns far more than on the consensus of climate scientists, who say we know enough to be deeply worried.
"I've been trying to understand how there can be such a strong consensus, given these uncertainties," she told the committee.
Her message that day on Capitol Hill was, in essence, that while humans may be contributing to climate change, we simply don't know how the climate will behave in the coming decades, so there may be no point in trying to reduce emissions.
That played well to Republican committee members including Dana Rohrabacher of California, who sees climate change as a liberal plot.
"We've gone through warming and cooling trends, but how much of this has anything to do with human activity?" he asked rhetorically. Concern about climate change "gives an excuse by government to control human activity, meaning our lives and our freedom."
Curry worries about that as well.
The Rough-And-Tumble Climate Debate
We caught up with her during her summer break, which she takes far from the sticky Atlanta heat. Her daughter lives in Reno, Nev., which means the cool mountains overlooking Lake Tahoe are a quick drive.
We hit the trail with her dogs, Bruno and Rosie, who are friendly and curious — half Australian shepherd, half poodle. This is a favorite place for Curry to come and walk and think. We settle on a chunk of granite to talk.
Curry, 60, is a bit of an outcast these days in the world of climate science. But it wasn't always so.
Curry says her 2005 hurricanes paper "generated a lot of media attention which we were ill-prepared to deal with," she says. "We were being attacked by the anti-global-warming crowd as well as a large number of people in the hurricane community who thought this was natural variability."
And that was just her first taste of the rough-and-tumble climate debate. A few years later, an apparent hacker released a lot of private email conversations among climate scientists involved with the United Nations climate assessment, the Intergovernmental Panel on Climate Change. Curry stepped into the middle of this and started engaging some of the skeptics.
"I took it upon myself to try to calm the waters I bit. I thought, 'Oh my gosh, this could really blow, and this would not be a good thing for climate science or the IPCC,' so I wrote an essay on the credibility of climate science."
Her philosophy, then and now, is that if climate scientists would more readily acknowledge the uncertainties inherent in the issue, skeptics would more likely accept the well-established central tenets of global warming.
To give one example, she says human activities are contributing to global warming, but she bridles at the IPCC consensus that humans are "largely responsible" — in other words, that more than 50 percent of global warming to date is caused by human activity.
"It might be around 50 percent or even a little less. I mean this is what we don't know" she says.
Economics Vs. Science
Curry started her own blog, which is a forum for outsiders to weigh in on climate science. She sees it as democratizing the discussion.
"All we can do is be as objective as we can about the evidence and help the politicians evaluate proposed solutions," she says. If that means doing nothing, "I can't say myself that that isn't the best solution."
And this is where Curry parts company most clearly with her peers. For example, the leading scientific organization for earth scientists, the American Geophysical Union, says in a position statement that climate change "requires urgent action." It concludes that despite some uncertainties, there's no scenario where climate change will be inconsequential.
Curry's dissent from this position is as much about the economics as about the science.
"I have six nieces and nephews who have recently graduated from college," she says. "Not easy finding jobs in this economy. Are we going to jeopardize their economic future, and we don't know if they're going to care and if this is going to matter?"
Of course doing nothing to address climate change is actually doing a lot. Carbon dioxide levels are growing fast in the atmosphere and are destined to double or triple over pre-industrial levels. Curry acknowledges that.
"I don't know how concerned I should be about it — on what time scale that might happen, whether that's 100 or 200 years, what societies will be like, what other things are going on with the natural climate," Curry says. "I just don't know what the next hundred or 200 years will hold, and whether this will be regarded as an important issue. I just don't know."
Advocates for action say we shouldn't run that experiment on our planet. Curry's response?
"Well, I think the experiment is going to happen whether people say we should run it or not. We're not going to convince China and India and other developing countries not to burn fossil fuels."
By now, of course, Curry has strayed far from science and deep into public policy. But like all of us, she does have a personal point of view. And hers, at root, is not about science; it's about individualism.
"I walk to work, I drive a Prius, I'm a fanatic about turning lights off and keeping air conditioning high and heating low, so I try to personally minimize my own carbon footprint. But in terms of telling other people what to do, I don't have any big answers."
But leaving climate change actions to individuals will not solve the problem. You can't affect global warming simply by buying a Prius and adjusting the thermostat. And there's no uncertainty about that.