Dan Gardner is the New York Times best-selling author of Risk, Future Babble, Superforecasting (co-authored with Philip E. Tetlock), and How Big Things Get Done (co-authored with Bent Flyvbjerg). His books have been published in 26 countries and 20 languages. Prior to becoming an author, Gardner was an award-winning investigative journalist. More >

The Science of Uncertainty

Well, it seems I was wrong. All wrong. "Climategate" and the other recent scandals have torn the lid off the rotten science of climate change. The deniers were right. Crank up the air conditioning and open the windows, happy days are here again! Last week, even as I was writing columns saying it was nonsense to suggest the scientific foundations of climate change were crumbling, big news flashed from excitable blogger to excitable blogger: A rebellion within the ranks of Britain's elite science academy, the Royal Society, had forced officials to admit that the science of climate change is not settled and to launch a review of the science and write a new official statement. The consensus is crumbling! And since this came from the Times of London, it must be true. The Times story wasn't quite so excited. But it was still pretty shocking. Under a dramatic headline, "Rebel Scientists Force Royal Society to Accept Climate Change Scepticism," the story begins: "Britain's premier scientific institution is being forced to review its statements on climate change after a rebellion by members who question mankind's contribution to rising temperatures. " The story went on to note that while the former president of the Royal Society had once said "the debate on climate change is over," the new statement contradicted that. And seemed to endorse the skeptics' position. "Any public perception that science is somehow fully settled is wholly incorrect," it said, "there is always room for new observations, theories, measurements ..." So I had a look at the Royal Society's statement. It was disappointingly mundane. The society routinely produces summaries of the science on important topics, it noted, and it was time to update the statement on climate change. "The new guide has been planned for some time," the statement said, "but was given added impetus by concerns raised by a small group of Fellows of the society that older documents designed to challenge some of the common misrepresentations of the science were too narrow in their focus. " So much for rebel scientists forcing the society to run up the white flag. On the substance of the forthcoming document, here's what the president of the society, Sir Martin Rees, had to say: "Climate change is a hugely important issue but the public debate has all too often been clouded by exaggeration and misleading information. We aim to provide the public with a clear indication of what is known about the climate system, what we think we know about it, and, just as importantly, the aspects we still do not understand very well." That's not an emphatic statement that the globe will boil if we don't start riding bicycles. But is it a climb-down? No. It's true that what Rees said is modest and restrained, and it acknowledges uncertainties and unknowns. It's also true that it is very different from the bluster and hyperbole of Al Gore and other activists. But contrary to what the media and the public seem to think, Gore and Company do not speak for science. Never have. And there's nothing in what Rees said that orthodox scientists haven't been saying for years, as a look at the many official statements of the IPCC or the national academies will show. As for the Royal Society saying the debate isn't settled, anyone who thinks that's a victory for those who deny climate change doesn't understand what science is. In science, there is no absolute certainty, all knowledge is tentative, and no conclusion is sacrosanct. A scientist who wants to dispute the germ theory of disease - or relativity, or gravitational theory, or anything else - is welcome to give it a go. So in saying that the science is not settled and there's always room for new observations and theories, the Royal Society was simply reaffirming its commitment to the most basic tenet of science. The essential problem is that the public - the media very much included - generally doesn't understand science. Most of us think science is a list of absolutely certain facts that are not open for debate. If a theory is on the list, it's not debatable and we should act on it; if it's not, it is debatable and we should not act on it. As a result, scientists often find it hard to communicate scientific conclusions to the public. If they speak scientifically, they have to acknowledge that even though most scientists have come to a conclusion they are reasonably confident is true, there is continued uncertainty and debate. But if they do that, people will think the conclusion isn't yet a scientific fact - and we shouldn't act on it. This drives scientists crazy. Sometimes, out of sheer frustration, they say something dumb like "the science is settled" or "the debate is over." They often regret it. The one genuinely important and surprising statement made by the Royal Society was this: "Nothing in recent developments has changed or weakened the underpinning science of climate change." Polls in the United Kingdom and elsewhere show that since "Climategate" and other recent scandals there have been dramatic declines in popular agreement that the planet is warming and human activity is the primary cause. Why? Because people are under the impression that the scandals revealed that core elements of the science are weak, or even fraudulent. The Royal Society just said "that ain't so." It would have been nice if reporters and bloggers had listened.