Activists protest outside the Heartland climate-denier conference. (Photo by Forecast the Facts.)

It’s been a rough few weeks for the Heartland Institute, the “intellectual” nexus of the fossil fuel-powered machine that disparages climate science in the United States. Nineteen corporations have pulled more than $1 million in expected funding for the institute, leading President Joe Bast to ask attendees at the recent Heartland climate-denial conference whether they had a “rich uncle” who could help out. Seriously.

At a time when most news about climate change is bad, Heartland’s decline has been a rare bright spot. How did it come about? In the reductive rendering of the mainstream media, the narrative has become that Heartland simply overplayed its hand by launching a billboard campaign comparing people who believe in global warming to the Unabomber, one of the single dumbest PR moves in recent history. Others have gone deeper, pointing out that Heartland has been painting itself into the crazy corner for a long time, and its lies were bound to catch up with it eventually. In that view, Heartland’s demise was essentially inevitable.

The infamous Unabomber billboard.

While these narratives have elements of truth — the billboards were incredibly stupid, and Heartland has been lying for a long time — neither offers a full explanation because both deemphasize the crucial role of citizen action. Simply put, the post-billboard exodus of Heartland’s corporate donors would have been neither as big nor as fast if not for the actions of thousands of everyday Americans calling those donors to account. Indeed, it might not have happened at all.

For those who haven’t been closely following the saga, here is the basic chronology. In February, documents containing a list of Heartland funders were leaked to a number of bloggers by climate scientist Peter Gleick, who risked his professional reputation to expose the sources of Heartland’s support. Two days later, the organization I work for, Forecast the Facts, launched a campaign calling on all corporate funders of Heartland to withdraw their support, with our initial focus on General Motors. Within a week, more than 20,000 people, including 10,000 GM owners, had signed on. After adding their names to the effort, those citizen-activists then called GM, posted hundreds of comments on GM’s Facebook page, uploaded photos of themselves with their GM cars, showed up at events where GM’s CEO was speaking, and generally made it clear that they were extremely upset about GM’s Heartland association. After weeks of pressure, including considerable media coverage, GM pulled its support on March 28 — more than a month before the now infamous billboard went up.