Low-carbon energy sources must produce most of the world's power by the middle of this century and fossil fuel burning will need to be almost completely phased out by 2100 in order to avoid "severe, pervasive, and irreversible" damage to the Earth's climate system, the United Nations Intergovernmental Panel on Climate Change (IPCC) said in its latest report, released on Sunday.
It's the latest in a year-long series of climate studies released by the panel. But some scientist are wondering if these big, consensus documents — released every seven years or so — are the best way to communicate what researchers understand about climate change and move forward the seemingly intractable political stalemate on securing an international climate pact. For decades, climate scientists have been in agreement about the need to address a warming planet. It's the public and some politicians who still need to be convinced. And these reports don't seem to make much of a dent.
"People assume the purpose of these reports is to change the public's mind," Katherine Hayhoe, a climate scientist at Texas Tech University, told VICE News. "Clearly that's not happening and clearly that's not what the public needs. One more report is not what's going to change people's minds."
While many people believe that more scientific reports leads to greater knowledge of climate change, which will in turn mean more support for policies that keep fossil fuels in the ground, social science suggests that the release of these high-profile studies can actually deepen the gap between those that understand the science and those they deny that climate change is occurring.
In a paper published in the journal Nature, Yale University professor Dan Kahan found that increased science literacy created more polarization among members of the public, not less.
An individual's feelings on climate change are affected more by personal interests and beliefs, Kahan found, than by increased access to scientific facts — a sociological problem that highlights the difficulty of spreading accurate climate science to the public and informing public policy debates.
"I think the IPCC might be achieving this really polarized status where it no longer has any credibility with the people who need to be convinced," Andrew Dessler, an atmospheric scientist at Texas A&M University, told VICE News.
Modern politics tends to deride and discredit anyone bearing difficult information — "sliming the messenger," Dessler says — rather than finding ways to address problems, like how to transform energy production or prepare for climate change. For years, free-market libertarian groups, often funded by fossil fuel companies, have attacked the credibility of the IPCC. It's an effort that has resonance with the public and is difficult for the scientists of the IPCC, who volunteer their time, to overcome.
"The question is, how do you bring people who don't trust the IPCC on board? I don't have the answer, but I think the IPCC report is not going to bring Oklahoma Senator Jim Inhofe onto the side of science," Dessler told VICE News.
Part of the answer may be for the IPCC to take some focus away from the comprehensive reports and produce smaller publications with faster turnarounds on rapidly changing and highly focused areas of climate science, like extreme weather events or ocean acidification.
"The assessments can be done much quicker with much less burden on the scientific community," Michael Oppenheimer, a geoscientist at Princeton University, told VICE News. Oppenheimer proposed such an idea to the IPCC about seven years ago, he says, and the idea is gaining support within the UN community.
Some in environmental and social justice organizations see a big payoff, though, in the release of the UN's comprehensive assessment reports.
"The fact that these reports are highlighting the issues of social and economic injustice and where the impacts are going to be felt the hardest is really important globally," Heather Coleman, a climate change specialist at Oxfam America, told VICE News. "There's a lot to say for the need for collective reports like this one."
Coleman emphasizes that IPCC's reports become the basis for UN climate change negotiations functioning as an important, science-based frame for how diplomats and civil society groups debate the best ways to go about curb greenhouse gas emissions or preparing for a world of higher sea levels, hotter temperatures, and more extreme weather events.
"It provides some benchmarks for policy discussions," Jake Schmidt of the Natural Resources Defense Council told VICE News. "I think the recent foray that they've made into trying to define how much of a carbon budget we have left to stay below two degrees Celsius provides somewhat of a formal benchmark to judge what countries put forward in Paris next year."
Schmidt's reference to a "carbon budget" is one of the newest issues addressed by the IPCC and one widely seen as an important intervention on the part of the panel in expressing the urgency of capping carbon dioxide emissions. The scientific body says in order to keep temperature rise from exceeding two degrees Celsius from pre-industrial levels the world can only emit the equivalent of 2,900 gigatons of carbon dioxide. But since pre-industrial times two-thirds of that amount has already been used up. And fossil fuel companies have another 2,795 gigatons of carbon dioxide equivalent in the coal, oil, and natural gas reserves around the world.
The report might provide the simple value of a repeated message, says Dessler, which could have an effect on public discussion over longer time scales.
"These UN studies do force politicians to respond, and I think they do make it harder for politicians to deny climate change," Dessler told VICE News. "Some kind of scientific assessment is incredibly important but whether this is the right way to do this is an open question."
Follow Laura Dattaro on Twitter: @ldattaro