Going Into the Lion’s Den
A. Scott Denning
Professor of atmospheric sciences
Colorado State U. at Fort Collins
The Heartland Institute is noted for its climate-change skepticism and for being a major voice denying mainstream global-warming research. So when it invited Scott Denning, an expert in the global carbon cycle, to its annual meeting in 2010, he thought long and hard about it.
“Let’s face it. Our jobs as professors include doing research and publishing papers. They don’t include public arguments at places like Heartland,” he says. “And I got e-mail from people saying, ‘Don’t do it! You’ll only legitimize them!’”
Scientists like Mr. Denning and others profiled here do have markedly different responses to the warming debate. Mr. Denning is one who wants to meet the opposition. “Scientists get annoyed by the word ‘debate’ on this topic,” he says. “They say the science is settled and ignore the fact that this is a huge cultural phenomenon. For me engagement is the right thing to do.”
Plus, he says he makes a case that most researchers bypass too quickly: Greenhouse gases make it hot. “Everyone argues over computer models and prediction. I don’t. I use layman’s language. And I start with the fact that carbon dioxide emits heat. This is a lab experiment, not a model. It’s not complicated. If you put more of this gas in the air it warms things up. That’s my shtick.”
The Heartland meeting, he says, “was an amazing experience. There were more than 70 speakers, and I was the only mainstream scientist. It made me nervous to be there, but people really were very gracious.” They were all waving little hockey sticks, lampooning the famous hockey-stick graph most climate scientists use to show a recent warming trend, but he says in elevators and hallways they shook his hand and thanked him profusely for explaining his position.
So last year he accepted an invitation to return, and debate the skeptic Roy Spencer, a climate scientist from the University of Alabama at Huntsville. (See below.) “Spencer and I actually agree on a lot of stuff. Although he says satellite data don’t support warming, and I think that’s a red herring. There’s only 50 years of satellite readings, not a long-term record,” Mr. Denning says. The basic physics of carbon dioxide, he asserts, is the unarguable reality. “So I want to go say that in front of 500 hard-core contrarians.”
The Majority Shouldn’t Rule
Judith A. Curry
Chair, School of Earth and Atmospheric Sciences
Georgia Institute of Technology
People have trouble defining Judith Curry. Joe Romm, editor of the pro-change Climate Progress blog, trumpeted “Judith Curry abandons science” in a post in which he also called her a “confusionist.” After she co-wrote a paper linking more hurricanes to higher temperatures, by contrast, she was accused of jumping on the global-warming bandwagon to drum up research money. And the word “heretic” often shows up near her name.
Much of that is because Ms. Curry, an established scientist with a long CV, has become publicly disenchanted with the Intergovernmental Panel on Climate Change, expressed doubts about the cause-effect connections that led many of her colleagues to accept predictions of serious climate change, and gave a forum on her blog to the skeptic and statistician Steve McIntyre of the Climate Audit blog, who attacks a lot of warming data. “I see myself as a scientist,” Ms. Curry says. “The main job of a scientist is to always question. The IPCC lost sight of this because it is all about consensus.”
She says she hasn’t always been this way. “I accepted the judgments of the IPCC on subjects that I wasn’t working on myself,” she recalls. But in 2009, “the tone of the Climategate e-mails really struck me. I saw people trying to get access to data, and they got the runaround. There were efforts to circumvent peer review. It wasn’t misconduct. But it was a consistent pattern by the IPCC scientists of marginalizing people who disagreed with them. It was a bullying approach.”
Science has to allow for minority views, she says; it can’t plow them under. So she began to approach skeptics herself. Mathematicians and software experts, specialists in chaos theory—all had divergent takes on warming data. And that added to Ms. Curry’s own uncertainties about IPCC predictions. “Volcanoes are a wild card,” she says; does what they throw into the air trap heat or reflect it away? “And we’re expecting some solar cooling. Feedbacks from water vapor aren’t understood. Climate models don’t reproduce these effects.”
Modelers, however, insist that they do, which has driven a lot of recent Curry criticism. But she continues to insist that we don’t know a lot about future climate effects—"Scientists worry about a meter of sea-level rise. Yet that’s less than tides in some places"—and that asking basic questions is the only way to get better answers.
Warmer, Yes. Worrisome, No.
Roy W. Spencer
Principal research scientist, Earth System Science Center
U. of Alabama at Huntsville
Roy Spencer says he speaks on behalf of the planet’s poor. There are a lot of uncertainties about global warming, but there’s no doubt about poverty. “It kills,” he says. And remedies advocated by those worried about climate change—abruptly shifting away from fossil fuels—would cause so much economic dislocation that whole populations would plunge into poverty. “The policies they talk about would kill millions of poor people around the world,” he says.
And they would do this, he continues, because of a climate shift that is theoretical, overstated, and probably has little to do with human activity.
Mr. Spencer is not a rabid anti-science talk-radio host. He’s a climate scientist, with a career spent taking temperature measurements from NASA satellites. He’s also the author of books like The Great Global Warming Blunder: How Mother Nature Fooled the World’s Top Climate Scientists (Encounter Books), of scholarly papers in journals like Geophysical Research Letters, and the proprietor of a Web site, Roy Spencer, Ph.D., where he asks questions like “Global warming: natural or man-made?”
His answer, in all of these forums, is that it’s both, but that the natural effects matter more. “Yes, we’re adding carbon dioxide to the atmosphere. Yes, it should be causing some warming. But how much is unknown? And it could be lost in natural variability.”
Satellite temperature records over the last 50 years have convinced him that any warming trend is really the responsibility of a natural cycle called the Pacific Decadal Oscillation, a 20- to 30-year march of warm water and air back and forth across the Pacific. Further, he argues that models used by the Intergovernmental Panel on Climate Change exaggerate the level of heat-trapping clouds, which throws off their ability to predict future temperatures. “When we tune our computer models to explain everything, we get climate sensitivity that’s lower than the lowest IPCC estimate,” he says.
Earth’s climate, Mr. Spencer concludes, just isn’t as sensitive to human intervention as most climate scientists claim. And that’s why we shouldn’t do anything drastic, he believes. “The danger the IPCC talks about is theoretical,” he says.
That stance has hampered his scientific career, he says. “There are a few scientists who are gatekeepers at journals. They trash papers written by skeptics like me.” So it’s harder to get published, or to get research money. (Indeed, the editor of the journal Remote Sensing resigned last year because of the backlash after he published a Spencer paper.)
On the other hand, “our university has been supportive. I haven’t gotten any flak from them. If I was at Harvard, I’d probably hear a lot more complaints,” Mr. Spencer says. “So I’d say this has slowed us down, not crippled us.”
Rapid Response to Skepticism
Scott A. Mandia
Professor of physical sciences
Suffolk County Community College
The first thing you should know about him, Scott Mandia says, is that “I’m a science educator. I hesitate to call myself a climate scientist.” He has a master’s in meteorology from Pennsylvania State University, but he wants to be in the classroom. “When Penn State put me on the research-assistant track, I demanded a teaching track as well.”
Mr. Mandia is nonetheless on the front lines of the global-warming debate, battling against those who deny that warming is accelerating. He is co-founder and one of four “matchmakers” on the Climate Science Rapid Response Team, where he fields queries from journalists, policy makers, and elected officials and matches them with experts in specific fields.
And he organized the nonprofit Climate Science Legal Defense Fund to defray the legal bills of scientists like Penn State’s Michael Mann, who have had to defend themselves in court against conservative advocates who want the scientists’ correspondence and have accused them of misusing grant money.
Mr. Mandia says he didn’t pay much attention to climate change until the 2007 report from the Intergovernmental Panel on Climate Change detailed the human role. “I remember walking by a geology classroom at my college, and I heard the instructor say that global warming was all a hoax. I knew he was wrong, but I didn’t know how to argue with him.”
So he set about teaching himself, and put what he learned, along with detailed references, on a Web site hosted by Suffolk called “Global Warming: Man or Myth?” where readers can find graphs showing that increased sunspots, or volcano activity, can account for just a small portion of observed warming over the last centuries.
After the “Climategate” e-mails were released in 2009, when some people said the documents showed that scientists had trumped up the evidence for climate change, he helped start the Rapid Response Team. “If reporters know who to get accurate information from, everyone wins,” he says. Last year, when he and a photographer named Joshua Wolfe learned that Mr. Mann was going to be on the hook for $25,000 in legal fees, with more to come, they started soliciting donations to help. The defense fund has been taken under the wings of Public Employees for Environmental Responsibility, a national nonprofit.
Mr. Mandia says he responds to about 200 climate-related e-mails every day, and gives weekly talks at schools. He estimates he spends four to five hours every day on climate change, in addition to the course he teaches on the topic. The course, he says, is where he really sees a difference: “Because every semester when it ends, I have 32 more climate-change ambassadors.”
Follow the Science
John Nielsen-Gammon
Professor of atmospheric sciences; Texas state climatologist
Texas A&M U.
The climate-change debate, says John Nielsen-Gammon, can get so noisy that the din drowns out actual climatology. “There’s a lot of valuable stuff in climate science that people aren’t talking about,” he says.
Three aspects of that “stuff” occupy a lot of Mr. Nielsen-Gammon’s time these days. “I’m the state climatologist, and so a lot of my research is on meteorology that has a direct impact on the people of Texas.” He is involved in two projects on the Texas drought, which has been scorching the Lone Star State for two years. He and several colleagues are trying to develop measures of drought effects on a small scale, on the order of a four-kilometer grid across the state. National drought indicators divide the country into much larger regions, but that doesn’t help individual counties in a parched state either prepare for water shortages or make a case that they need assistance from federal agriculture programs. The smaller grid, he says, will give county officials sharp local information that would otherwise be lost.
The second project is also small-scale, but for time and not ground: He is creating short-term indices of stream flow, based on low-level atmospheric conditions, to aid in local planning for water resources.
He is also researching ticks. Populations of Gulf Coast ticks may wax and wane in relation to humidity. “If we can nail down the relationship, you might know when your cattle are vulnerable to a tick infestation, and you can prepare for it,” he says.
But he’s not ignoring the noisiest issue. He’s investigating whether human activities may have contributed to the drought, which is generally attributed to a natural climate cycle called the El Niño-Southern Oscillation. And he has a blog, hosted by the Houston Chronicle, where he regularly takes on issues of global climate change, generally supporting the idea that there is a change but acknowledging debates and holes in the data. “I believe in engaging with skeptics, but mostly I do it under the radar,” he says. A more confrontational public stance, he believes, would leave him little time to do his job.