Scientific heresy

Lesson 6. Never rely on the consensus of experts about the future. Experts are worth listening to about the past, but not the future. Futurology is pseudoscience.

Using these six lessons, I am now going to plunge into an issue on which almost all the experts are not only confident they can predict the future, but absolutely certain their opponents are pseudoscientists. It is an issue on which I am now a heretic. I think the establishment view is infested with pseudoscience. The issue is climate change.

Now before you all rush for the exits, and I know it is traditional to walk out on speakers who do not toe the line on climate at the RSA – I saw it happen to Bjorn Lomborg last year when he gave the Prince Philip lecture – let me be quite clear. I am not a “denier”. I fully accept that carbon dioxide is a greenhouse gas, the climate has been warming and that man is very likely to be at least partly responsible. When a study was published recently saying that 98% of scientists “believe” in global warming, I looked at the questions they had been asked and realized I was in the 98%, too, by that definition, though I never use the word “believe” about myself. Likewise the recent study from Berkeley, which concluded that the land surface of the continents has indeed been warming at about the rate people thought, changed nothing.

So what’s the problem? The problem is that you can accept all the basic tenets of greenhouse physics and still conclude that the threat of a dangerously large warming is so improbable as to be negligible, while the threat of real harm from climate-mitigation policies is already so high as to be worrying, that the cure is proving far worse than the disease is ever likely to be. Or as I put it once, we may be putting a tourniquet round our necks to stop a nosebleed.

I also think the climate debate is a massive distraction from much more urgent environmental problems like invasive species and overfishing.

I was not always such a “lukewarmer”. In the mid 2000s one image in particular played a big role in making me abandon my doubts about dangerous man-made climate change: the hockey stick. It clearly showed that something unprecedented was happening. I can remember where I first saw it at a conference and how I thought: aha, now there at last is some really clear data showing that today’s temperatures are unprecedented in both magnitude and rate of change – and it has been published in Nature magazine.

Yet it has been utterly debunked by the work of Steve McIntyre and Ross McKitrick. I urge you to read Andrew Montford’s careful and highly readable book The Hockey Stick Illusion. Here is not the place to go into detail, but briefly the problem is both mathematical and empirical. The graph relies heavily on some flawed data – strip-bark tree rings from bristlecone pines -- and on a particular method of principal component analysis, called short centering, that heavily weights any hockey-stick shaped sample at the expense of any other sample. When I say heavily – I mean 390 times.

This had a big impact on me. This was the moment somebody told me they had made the crop circle the night before.

For, apart from the hockey stick, there is no evidence that climate is changing dangerously or faster than in the past, when it changed naturally.

It was warmer in the Middle ages and medieval climate change in Greenland was much faster.

Stalagmites, tree lines and ice cores all confirm that it was significantly warmer 7000 years ago. Evidence from Greenland suggests that the Arctic ocean was probably ice free for part of the late summer at that time.

Sea level is rising at the unthreatening rate about a foot per century and decelerating.