Aggressive deniers practice a form of asymmetric warfare that is decentralized and largely immune to reasoned response. They launch what Aaron Huertas, a press secretary at the Union of Concerned Scientists, calls “information missiles,” anti-climate-change memes that get passed around on listservs, amplified in the blogosphere, and picked up by radio talk-show hosts or politicians. “Even if they don’t have much money, they are operating in a structure that allows them to punch above their weight,” Huertas says.

…

The evidence to support the theory of anthropogenic, or human-caused, climate change has been mounting since the mid-1950s, when atmospheric models predicted that growing levels of CO₂ in the atmosphere would add to the natural “greenhouse effect” and lead to warming. The data was crude at first, and opinions vacillated (skeptics like to recall a 1974 Time cover story that predicted an impending ice age). But by the mid-1990s, thousands of lines of independent inquiry supported the conclusion summarized in the 1995 IPCC report: “The balance of evidence suggests a discernible human influence on global climate.”

Since then, the case for anthropogenic climate change has only strengthened; 98 percent of actively publishing climate scientists now say that it is undeniable. But several finer points remain unsettled. For instance, researchers still don’t completely understand the role of aerosols in the atmosphere, the variable effects of clouds at different heights, and the influence of feedback mechanisms such as the changing reflectivity of the Earth’s surface and the release of gases from permafrost or deep seabeds. Climate-change skeptics have been keen to capitalize on those gaps in knowledge. “They play up smaller debates,” says Francesca Grifo at the Union of Concerned Scientists, “and divert the dialogue by attacking particular aspects. They represent climate science as a house of cards, where you pull out one and it all falls apart.”

…

In March 2001, George W. Bush’s administration declared that climate science was “too uncertain” to justify action (such as ratifying the Kyoto treaty) that might put the brakes on economic growth. That refrain would be echoed again and again, weakening or derailing successive international agreements and domestic policy. How had a small band of non-scientists managed to so quickly and thoroughly pursuade the nation’s leaders to reject an ever more coherent and definitive body of scientific evidence?

…

“It’s that false balance thing,” Mann says. “You’re a reporter and you understand there’s an overwhelming consensus that evidence supports a particular hypothesis—let’s say, the Earth is an oblate spheroid. But you’ve got to get a comment from a holdout at the Flat Earth Society. People see the story and think there’s a serious scientific debate about the shape of the Earth.”

…

“When I get an e-mail that mentions my child and a guillotine,” Hayhoe says, “I sometimes want to pull a blanket over my head. The intent of all this is to discourage scientists. As a woman and a mother, I have to say that sometimes it does achieve its goal. There are many times when I wonder if it’s worth it.”

…

As drivers crawled along Chicago’s busy Eisenhower Expressway, they were confronted with a large billboard that compared believers in global warming with Ted Kaczynski, the Unabomber. The text on the billboard read, “I still believe in global warming. Do you?” The advertisement was meant to be the first in a series. Others would liken climate-science advocates to mass murderers, including Charles Manson and Osama bin Laden. Bast did not respond for comment following the launch of the campaign, but Heartland issued a press release: “The people who believe in man-made global warming are mostly on the radical fringe of society. This is why the most prominent advocates of global warming aren’t scientists. They are murderers, tyrants, and madmen.”

“There are powerful voices of unreason,” says Ben Santer, who led the 1995 IPCC team, “but every year, the science becomes stronger and the data are telling an ever more consistent story.” As with tobacco, the more consistent the scientific story, the more difficult it will become for skeptics to reject anthropogenic climate change. That point was driven home after the Charles Koch Foundation donated $150,000 toward a study by Richard Muller, a physicist at the University of California at Berkeley who was, at the time, a darling of the climate-skeptic community. Muller spent two years investigating claims by global-warming deniers that temperature rises verified by multiple studies were skewed because of flawed analysis, unreliable weather stations and the effect of urban heat islands. Muller and his research team (which included Saul Perlmutter, the joint winner of the 2011 Nobel Prize in Physics) compiled 1.6 billion readings at 39,000 sites and examined other historical data.

Muller’s conclusion was most likely not what the Koch brothers had in mind. Last October, his team announced that the global mean temperature on land had increased by 1.6 degrees since 1950, a result that matched the numbers accepted by the mainstream climate-science community. “The skeptics raised valid points, and everybody should have been a skeptic two years ago,” Muller told me. “Now we have confidence that the temperature rises previously reported had been done without bias. Global warming is real.”

…

Just as in the rest of the country, belief in human-caused climate change in Oklahoma has been rising with the thermometer—according to Krosnick, a large majority of Inhofe’s constituents now believe that anthropogenic global warming is real. I ask Inhofe if he’s noticed any climate changes in his home state, such as last summer’s unprecedented heat and severe drought, withering crops, wild fires and dramatically expanded tornado season. “There’s not been any warming,” he snaps. “And there’s actually been a little bit of cooling. It’s all documented. Look at the Dust Bowl. Back then it was a lot hotter. Matter of fact, now they say the hottest time was actually during that time—1934, I guess.”

Actually, last summer’s average temperature of 86.9˚ was the highest ever recorded in Oklahoma. And last spring’s drought, when hundreds of farmers abandoned livestock they could no longer manage to feed or water, was the worst since 1921.

…

Many of the scientists I’ve spoken with say that no single act of harassment or intimidation has stung more than Inhofe’s “list of 17,” the call for the congressional investigation of prominent climate scientists. Mann, I tell Inhofe, said it “smacked of modern-day McCarthyism.”

Source