In a sprawling new story in Popular Science, Tom Clynes takes an in-depth look at the seedy but influential range of people who take it upon themselves to make life a living hell for climate-change researchers. Here, five key takeaways:

1. Harassment is routine
Climate-change deniers often threaten scientists in attempts to distract them from their research — and the harassment goes beyond nasty emails. One climate modeler describes finding "a dead rat on his doorstep" with "a yellow Hummer speeding away." Last year in Australia, several scientists were ushered to a safer facility when opponents "unleashed a barrage of vandalism, noose brandishing, and threats of sexual attacks on the scientists' children." Michael Mann, director of Penn State University's Earth System Science Center and one of the 2007 joint recipients of the Nobel Peace Prize, once opened his mail and "a small mass of white powder cascaded out of the folds and onto his fingers." He went to the bathroom, washed his hands, and calmly phoned the police. Threats like "are so much a part of my life that I don't even realize how weird it is," he says

2. Political associations don't matter
For Katharine Hayhoe, an atmospheric scientist, political conservative, and evangelical Christian, her work can be as thankless as it is taxing. In 2007, Rush Limbaugh discovered her contributions to a book co-authored by Newt Gingrich and ridiculed her as a "climate babe." Following the backlash, Gingrich dropped her chapter on global warming entirely. That's "100+ unpaid hours I could've spent playing with my baby," Hayhoe tweeted. "There are many times when I wonder if it's worth it," she says.

3. Research is often stifled by legal action 
"Those crude acts of harassment often come alongside more-sophisticated legal and political attacks," says Clynes. Climate-change skeptics regularly file lawsuits and Freedom of Information Act requests to disrupt ongoing research. "In 2005, before dragging Mann and other climate researchers into congressional hearings, Texas Congressman Joe Barton ordered the scientists to submit voluminous details of working procedures, computer programs, and past funding," says Clynes. Essentially, Barton wanted Mann to reproduce and defend his "entire life's work."

4. Climate skeptics pay activists to bother scientists
It's not "a bunch of crazy people" fighting against us, says Mann. "These efforts to discredit science are well-organized." "There's really only about 25 of us doing this," says Steve Milloy, a Fox News commentator and self-described "denier." He calls the core group of skeptics "a ragtag bunch, very Continental Army." The deniers often target scientists who speak up publicly, offering bounties to anyone willing to make their lives difficult. In one instance, Milloy offered $500 for anyone caught on video heckling Mann during the California leg of his book tour. "This whole green thing, the whole environmental scare industry, is really just an ingenious plan to exert government control over everything we do," says Milloy. "I have yet to see an environmental scare that is remotely true when it comes to human health: Secondhand smoke, air quality, ozone depletion, pesticides, Superfund sites — you name it."

5. And climate-change deniers are well-funded
Following the Kyoto Protocol on global warming in 1998, the American Petroleum Institute put together a $5.9 million task force (which included Milloy) charged with discrediting climate-change science to "quash growing public support of curbing emissions." A leaked memo from the group revealed detailed plans to "recruit, train, and pay willing scientists to sow doubt about climate change among the media and the public." Apparently, the group achieved what it set out to do: In March 2001, President George W. Bush declared that climate change was "too uncertain" to take action on.

Read the entire article at Popular Science.