Last week, in Stockholm, a group of scientists from around the world issued what should be, but of course will not be, the last word on climate change. Officially known as Working Group I’s contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, the document offered a veritable flood of information—two thousand two hundred and sixteen pages’ worth. Many groups posted good summaries of the report’s central points, including Climate Central and RealClimate. But perhaps the best one I read came in an e-mail from a biologist who studies the effects of climate change in the Andes. “Spoiler alert,” he wrote. “Earth is getting warmer.”

For weeks leading up to the release of the report—several more will be issued in the next few months by other working groups of the I.P.C.C.—the denialosphere was working overtime. A group that calls itself, wittily enough, the Nongovernmental International Panel on Climate Change, published its own report, twelve hundred pages long, explicitly modelled on the I.P.C.C.’s but reaching entirely opposite conclusions. The N.I.P.C.C., as it happens, is sponsored by the Heartland Institute, which, in turn, is funded by a coven of tobacco companies, fossil-fuel producers, and right-wing foundations.

The goal of organizations like the N.I.P.C.C., it seems, is not to convince anyone that the science of global warming is faulty—their tactics are way too amateurish for that—but, rather, to provide cover for those already predisposed to prefer fairy tales over facts. This group turns out to be not only numerous but, as recent events have demonstrated, also quite powerful.

It seems oddly appropriate that a report warning that the time to move on climate change is today (yesterday, really) should arrive in the nation’s capital just as the government was preparing to shut down. Nothing signals inaction quite so eloquently as barricades around the Jefferson Memorial. The proximate cause of the shutdown is the refusal of the Republican-led House to continue financing the government unless Democrats agree to delay (or gut) Obamacare. But the deeper cause might be said to be the same kind of fairy-tale thinking that animates the N.I.P.C.C. Shuttering the government is a dumb idea under pretty much any circumstances. Still, the objections that Republicans in Congress raise to the health-care law might be worth considering if they bore any relationship to the law in question. Rarely do they.

Some lawmakers’ comments have been so off the wall that they defy parody. A few months ago, for example, Representative Michele Bachmann announced on the House floor that Obamacare needed to be repealed “before it literally kills women, kills children, kills senior citizens.”

“Let’s not do that,” she added helpfully. “Let’s love people.”

“All of this would be funny,” President Obama noted the other day, after bringing up the Bachmann line, “if it weren’t so crazy.”

The crazy list goes on and on. As the economist Paul Krugman has repeatedly pointed out in his Times column, congressional Republicans these days seem to think that they can override not just the laws of physics but also the rules of arithmetic. They insist that the federal budget is so bloated it could easily be cut by hundreds of billions of dollars. But when a transportation bill was drafted this summer that would have actually reduced spending, they refused to vote for it. (The bill had to be pulled from the floor.) It’s hard to cut the federal budget if you’re not willing to reduce the amount of money the government spends. “What Republicans really want to do,” Krugman wrote recently, is “repeal reality.”

This brings us back to climate change, which is really an issue of how we generate and use energy. Tuesday, just as the “Closed” signs were being posted on the steps of the National Gallery, Ron Binz, President Obama’s nominee to lead the Federal Energy Regulatory Commission, announced that he was withdrawing his name from consideration. Binz, who served on Colorado’s public-utilities commission for several years, is a strong advocate of replacing fossil fuels with renewable energy, which, as any schoolchild can tell you, is a critical part of any plan to reduce greenhouse-gas emissions. As far as Senate Republicans and also some Democrats were concerned, holding such rational and forward-thinking views disqualified Binz from service. “Mr. Binz’s record shows he strongly favors renewable over other energy sources,” Senator Joe Manchin, Democrat of West Virginia, said, and, remarkably enough, he meant this as an insult.

It’s been so long since reality has made much of a difference on Capitol Hill that it sometimes seems it genuinely has been repealed. But the thing you can always count on with reality is that it has staying power. At this point, it’s not clear whether there will be another assessment report from the I.P.C.C., because it’s hard to get more definitive than the one that was just released. But if there is a sixth assessment, four or five years from now, the summaries are, in a sense, already available. “Spoiler alert: Earth is getting warmer.”

Above: United Nations Secretary-General Ban Ki-moon addresses the Intergovernmental Panel on Climate Change via video link. Photograph by Jonathan Nackstrand/AFP/Getty.