Climate change is one of those large, sweeping stories in which history has not made a dent in more than 30 years. Alan Rusbridger, the editor in chief of the Guardian, decided to tackle it in a six-month, all-hands blitz.

Rusbridger is stepping down in June after 20 years atop the Guardian’s masthead, a move he says brought up thoughts of his legacy.

“I thought, ‘Well, I haven’t got long now, and therefore I want to do something about this whole subject,’” Rusbridger told Mashable. “I wondered, ‘What I could do that was most powerful and most focused within a six-month timeframe?’”

Rusbridger’s last few months editing the Guardian will conclude with the “Keep it in the ground” campaign against fossil fuels. Created in conjunction with environmental activist organization 350.org, the campaign calls for two of the world’s largest charitable organizations — the Bill and Melinda Gates Foundation and the Wellcome Trust — to divest their investments in fossil fuel companies.

Already, "Keep it in the ground" marks one of the boldest and most pointed advocacy crusades ever launched by a media organization. It has drawn support from activists and the public, curiosity from other media organizations, and wholly expected seething from oil companies. So far, the "Keep it in the ground" campaign has collected about 146,00 signatures, support from members of parliament, and at least one piqued response from Exxon Mobil.

Adding interest to the Guardian's campaign is that one of the organizations the paper is challenging —The Bill and Melinda Gates Foundation — is a major partner of the Guardian’s development coverage. That fact that has not stopped the paper from running critical analysis about the organization before. Rusbridger tells Mashable he has been in contact with both the Gates Foundation and the Wellcome Trust, and said that there is no indication that they plan to divest.

Inconvenient truth, convenient timing

Climate change was a story with the “enormity” to put a capstone on his editorship, Rusbridger says. It's a story that is also having its moment in history, with the White House moving to strike a climate agreement with China, and Mexico becoming the first developing nation to promise it would cut back on its air pollution.

Rusbridger had climate change — and advocacy — on his mind a long time before the "Keep it in the ground" campaign.

Advocacy work is far from alien to the newspaper’s pages or website. Earlier in 2014, the paper led an effort to stop female genital mutilation with a multimedia campaign that appeared across Africa.

Similarly, The Guardian had already doubled down on climate and environmental sustainability coverage just as rivals, like the New York Times, were scaling back. It now counts 4 million unique visitors for its environment coverage, includinga network of sites about sustainability and climate. At its peak, the Guardian's environmental coverage included a seven-person editorial team and 28 external specialists, Rusbridger has said.

'You can move from reporting to campaigning'

In Stockholm in early December 2014, Rusbridger met Bill McKibben, the founder of environmental group 350.org, for the first time.

Rusbridger and McKibben were in the Swedish capital to receive the Right Livelihood Award, given to people “offering practical and exemplary answers to the most urgent challenges facing us today.” Over lunch at the Museum of Spirits, McKibben took aim at oil companies, which he considered obstacles to environmental progress.

“The real fight is less with politicians and more with the big fossil fuel companies that are at the root of the problem,” McKibben tells Mashable. “I wasn't trying to convince [Rusbridger] of anything. I was just trying to tell him what's going on.”

Alan Rusbridger (left), Basil Fernando, Asma Jahangir, and Bill McKibben (right). Image: RightLivelihood.org

Rusbridger left the lunch impressed, but, he says, without any particular plan to launch another campaign.

That changed weeks later, when Rusbridger decided to step down as the Guardian’s editor. Over Christmas, as he considered what his legacy would be, McKibben’s words came back to him. The divestment campaign, he said, had the chance to actually have an impact on climate change.

“To my mind, the science of climate change is without doubt. The threat to the species is so severe that this is one of those rare subjects where you can move from reporting to campaigning,” Rusbridger says.

Two months later, The Guardian and 350.org launched the “Keep it in the ground” campaign.

The debut was impossible for Guardian readers to miss. It included a column from Rusbridger, extensive reporting from the paper’s environment team, a podcast about the inner workings of the campaign, a promise to keep climate stories on the front page of the website regularly, and a takeover of the newspaper’s homepage that greeted readers with what looked like inky petroleum dripping down the stories on the page.

A screenshot of the Guardian's homepage takeover on the launch day of the campaign. Image: The Guardian

The splash was meant to spur action. "Real change can only follow from citizens informing themselves and applying pressure," Rusbridger told readers.

Objectivity and objectives

As the Guardian tries to win over its targets among policymakers, and the public, it also has to convince many within the news industry that advocacy is within its mandate.

Rusbridger's introduction to the series seemed addressed, at first, to his fellow journalists.

"Changes to the Earth’s climate rarely make it to the top of the news list. The changes may be happening too fast for human comfort, but they happen too slowly for the newsmakers," Rusbridger said. He added later: "Is a collective shrug of fatalism the only rational response?"

Still, companies whose businesses rely on fossil fuels don't seem enthused. Exxon recently used the "Keep it in the ground" campaign as an excuse to snub Guardian reporter Suzanne Goldenberg with a piqued statement that the company would not speak with the paper due to a “lack of objectivity.”

'@ExxonMobil will not respond to @Guardian because of its lack of objectivity on climate change' #keepitintheground http://t.co/gfe3KLwAc9 — Suzanne Goldenberg (@suzyji) March 27, 2015

“Exxon is a giant corporation with a market cap of $380bn,” Rusbridger said in an email. “That they won’t respond to reporters whom they feel might be critical probably says more about them than us.”

The oil giant is understandably prickly on this topic, as previous divestment efforts have gained traction. Stanford University removed investments in coal, while the Rockefeller Family, which made it’s fortune from Standard Oil, dropped fossil fuel from the holdings of its $860 million philanthropy.

Exxon, meanwhile, is hardly stalwart in its opposition. It recently said it would begin to report on how climate change could impact its business, a move that had been called for by activists.

Not many news organizations have attempted a campaign on this scale, which makes the Guardian’s effort, at the least, a testing ground.

Bud Ward, an experience environmental journalist and editor of Yale Climate Connections, said that while the Guardian’s position on climate issues had been clear, a partnership with an activist organization was “unprecedented to my knowledge.” The Guardian’s embrace of a specific policy position, he says, is different from accepting the conclusion of professional societies who say climate change is a major threat. The Guardian's alliance with an activist organization, he says, "makes me a little nervous, maybe a lot nervous."

Rusbridger says the Guardian has chosen climate change for its importance.

“I haven’t done many campaigns of this nature, because I think they should be done very sparingly and I think they should only be done when the subject is really beyond doubt or where there's a sort of great urgency,” Rusbridger said.

Not everybody sees the loss of objectivity as a problem. Todd Gitlin, a journalism professor at Columbia University who has also been involved with divestment efforts, applauded the campaign, noting that rarely do media organizations say what they are actually thinking.

“Our current, dainty norm of, ‘hands off, the world is out there and we simply report on it,’ is a relatively brief episode in what has traditionally been a partisan, argumentative, moralist and, to put it mildly, opinionated fashion,” Gitlin said.

“Obviously, forthrightness is at a premium,” he added. “Forthrightness is scarce.”