THE National Academies of Science (NAS) and the Royal Society—the elite scientific fellowships of America and Britain, respectively, respectively—released today a rather handy “Frequently Asked Questions” resource on climate change. It seems designed to act as a sort of counterbalance to op-ed pieces like this one by Charles Krauthammer of the Washington Post, which take aim at “those scientists who pretend to know exactly what [carbon-dioxide emissions] will cause in 20, 30 or 50 years.” The scientists of Mr Krauthammer’s scorn don’t actually exist: No one pretends to such precision. But no matter, Mr Krauthammer’s real complaint is more general. His target is anyone who believes that “science is settled”—a belief he tries to ascribe to Barack Obama. “There is nothing more anti-scientific,” he says, “than the very idea that science is settled, static, impervious to challenge.”

This sounds good in a Popperian way; but it is not really true. While science is more unsettled than some feel comfortable admitting, it nevertheless depends on some things being settled irrevocably. The earth has a crust, a mantle and a core. Plants photosynthesise. Air is made of molecules. All these things were once not known and are now accepted as fundamental. And it was in among such fundamentals that the president put climate change when he said during his state-of-the-union speech that “The debate is settled. Climate change is a fact.”

This view is confirmed by the authors of the Royal Society/NAS FAQ. “Yes,” they answer the first question on their list. “Earth’s average surface temperature has increased by about 0.8°C since 1900.” Mr Obama is also joined by the vast majority of climate sceptics, let alone climate scientists. As Matt Ridley, a climate sceptic who was once the science editor of The Economist, and who writes much better op-eds than Mr Krauthammer, puts it: “No climate change sceptic that I know ‘denies’ climate change, or even human contributions to it.” That debate—which once was, indeed, a debate—is now settled; the earth warmed and the climate changed. Most of the Royal Society/NAS FAQS are designed to be similarly uncontroversially answerable.

So why is this still an issue? Partly because there are still genuine questions to which there are no clear answers. So those who favour significant action on climate change (as The Economist does) need to treat the subject carefully. For example, it is still an open question whether a loss of summer arctic ice is, by way of changes in the jet stream, responsible for unusual weather in mid latitudes, such as last month’s frigid American “Polar Vortex” or Britain’s recent floods. A number of eminent climate scientists recently wrote to Science, a scientific journal, explaining their concern over such links becoming “the centrepiece of public discourse”. As Lord Ridley points out, the alacrity with which Britain’s floods were blamed on global warming goes well beyond what the 2011 report on extreme events from the Intergovernmental Panel on Climate Change says on such subjects. “Attributing extreme weather events to climate change is challenging,” says the FAQ.

Attempts to claim all bad news as evidence of climate change are the sort of thing that makes climate sceptics very cross indeed. Many of those who campaign for climate action assume that sceptics are either stupid or motivated by money, but there is more to it than that, as David Victor of the University of California, San Diego, argued in a recent talk (the text of which has been posted online at the New York Times by Andy Revkin, an invaluable blogger on such subjects). Yes, Mr Victor agrees, there are shills who cast doubt on climate science for money. But there are fewer of them than there used to be, they seem to be getting less money from the carbon lobby (though it is hard to be sure about these things) and they may not now matter that much. Increasingly dominant among sceptics, he argues, are “hobbyists”—“people who disagree because it gives them something to do”. Some of them work with data and produce theories or arguments, some just cheer the others on, and nothing stirs them up more than a claim from a climate scientist that they think they can show to be wrong.

William Connelly, who writes a combative mostly-climate blog called Stoat, recently pointed out another aspect of scepticism-as-hobby: climate sceptics are by and large quite nice to each other, and to newcomers in their ranks. As long as you accept that climate concerns are in some way ill-founded, you will be welcome in most sceptic forums, even if the particular beef you have is not widely shared. Scientists like Mr Connelly and his colleagues are rarely that forgiving.

Understanding climate scepticism as a hobby, Mr Victor argues, means accepting that there is little that will make it go away. There will always be contentious issues in climate science to provide new grist. It is also important to note that by calling scepticism a hobby, and stressing that it is not necessarily financially motivated, he is not implying that it is in some way apolitical, as sewing and sailing might be. Climate-change sceptics appear to be overwhelmingly conservative. For many their investment of time in their hobby is linked to a belief that action on climate would give the state new licence to waste their taxes or limit their freedoms, and the sense that what they do and discuss is relevant and important adds to the rewards it brings them. Politics drives belief (or disbelief), not the other way round.

Mr Connelly talks of sceptics who are “often quite confused between the science of [global warming] and the political consequences.” This is not a confusion that is unique to sceptics. One frequently comes across the belief that, because there is a strong case that human actions have warmed the world and that, unchecked, things could heat up enough to do a lot of harm, a whole long shopping list of political consequences must be treated as more or less unassailable. The problem is that the policies that are held to follow direcftly from accepting the science can be very poor ones. Witness decades of support for America's corn ethanol subsidy, which Mr Victor describes as “one of the most truly idiotic energy policies” the country has adopted.

As Mr Victor explains in his excellent book, “Global Warming Gridlock”, effective political action on climate change is a hard problem. It requires internationally co-ordinated actions with real costs, a significant portion of which fall on well-organised lobbies, in return for benefits of unknown size at a far-off date that are not distributed among countries in a way remotely proportionate to the costs the various countries incur. Even in the absence of climate scepticism, such actions would be almost impossible to negotiate.

It may help, a little, that people not quite sure who to trust now have a nice FAQ to turn to. But it is not going to solve the problem that there is still scientific uncertainty as to how much harm could come how soon to whom, and political disagreement as to how much that risk can be reduced, and at what cost to whom. Questions are easier than answers.