Matt Ridley: Global lukewarming need not be catastrophic

My luke-warming column in the Times on 28th September 2013, pleaded in vain for a moderate middle approach to climate change, and drew a parallel with the nature-nurture debate. Here's what I wrote:

In the climate debate, which side are you on? Do you think climate change is the most urgent crisis facing mankind requiring almost unlimited spending? Or that it’s all a hoax, dreamt up to justify socialism, and nothing is happening anyway?

Because those are the only two options, apparently. I know this from bitter experience. Every time I argue for a lukewarm “third way” — that climate change is real but slow, partly man-made but also susceptible to natural factors, and might be dangerous but more likely will not be — I am attacked from both sides. I get e-mails saying the greenhouse theory is bunk and an ice age is on the way; and others from guardians of the flame calling me a “denier”.

Yet read between the lines of yesterday’s report from the Intergovernmental Panel on Climate Change (IPCC) and you see that even its authors are tiptoeing towards the moderate middle. They now admit there has been at least a 15-year standstill in temperatures, which they did not predict and cannot explain, something sceptics were denounced for claiming only two years ago. They concede, through gritted teeth, that over three decades, warming has been much slower than predicted. They have lowered their estimate of “transient” climate sensitivity, which tells you roughly how much the temperature will rise towards the end of this century, to 1-2.5C, up to a half of which has already happened.

They concede that sea level is rising at about one foot a century and showing no sign of acceleration. They admit there has been no measurable change in the frequency or severity of droughts, floods and storms. They are no longer predicting millions of climate refugees in the near future. They have had to give up on malaria getting worse, Antarctic ice caps collapsing, or a big methane burp from the Arctic (Lord Stern, who still talks about refugees, methane and ice caps, has obviously not got the memo). Talk of tipping points is gone.

They have come to some of this rather late in the day. Had they been prepared to listen to lukewarmers and sceptics such as Steve McIntyre, Ross McKitrick, Pat Michaels, Judith Curry and others, then they would not have had to scramble around at the last minute for ad-hoc explanations. These issues have been discussed ad nauseam by lukewarmers.

The climate war has been polarised in the same way that the nature-nurture debate was in the 1970s. Back then, if you argued that genes affected behaviour even a bit, you were pigeon-holed as a heartless fatalist with possible tendencies to Nazism. I barely exaggerate at all. Today, if you express a hint of doubt about the possibility of catastrophic warming, you are a heartless fool with possible tendencies to Holocaust denial. Sceptics are “truly evil people”, the former US Senator Tim Wirth said this week.

In the nature-nurture war, polarisation was maintained by the fact that people only read their own side’s accounts of their opponents’ arguments. So they spent their time attacking absurd straw men. Likewise in the climate debate. The most popular sceptical blogs — such as Wattsupwiththat in America, Bishop Hill in Britain, JoNova in Australia and Climate Audit in Canada — provide sometimes brilliant analysis and occasional mad mistakes: scientific conversation as it should be.

[Update: sure enough Steve McIntyre of Climate Audit found a huge problem in the IPCC report on day 1: the graphs appear to have been changed since the previous draft, without referring back to reviewers, in such a way as to reduce the apparent failure of the models to match reality. Watch this space. See "The IPCC disappears the discrepancy".]

But most “proper” climate scientists won’t go near them, so misunderstand what the sceptics are talking about. They keep saying they don’t “believe” in climate change. Nothing could be farther from the truth: most think man-made climate change is real, just not very frightening. So the IPCC saying yesterday that it is 95 per cent certain that more than half of the warming since 1950 is man-made is truly a damp squib: well, duh.

We’ve warmed the world and will probably warm it some more. Carbon dioxide alone can’t cause catastrophe. For that you need threefold amplification by extra water vapour — which is not happening. So maybe it’s not a big enough problem to justify ruining landscapes with wind turbines, cutting rain forest to grow biofuels and denying World Bank loans to Africans for life-saving coal-fired electricity. (I declare a commercial interest in coal and wind, although I give the latter money away as an essay prize: won this week by Michael Ware’s brilliant demolition in The Spectator of the electric car madness.)

Of course, the IPCC’s conversion to lukewarming is not the way it will be spun, lest it derail the gravy train that keeps so many activists in well-paid jobs, scientists in amply funded labs and renewable investors in subsidised profits. After all, Dr Rajendra Pachauri, chairman of the IPCC, confidently asserted in 2009 that “when the IPCC’s fifth assessment comes out in 2013 or 2014, there will be a major revival of interest in action that has to be taken.” He said this before the people who would write the report had been selected, before any meetings had happened and before the research on which it was based had even been published.

Nature-nurture eventually grew reasonable: most people now agree it’s a bit of both. In the end, the same moderation will happen with climate, but by then fortunes of your money may have been spent on technologies that do more harm than good.

We need a grown-up conversation without name-calling about the possibility that, if the climate resumes warming at the rate the IPCC expects, it may do more good than harm for at least 70 years: longer growing seasons, fewer droughts, fewer excess winter deaths (which greatly exceed summer deaths even in warm countries) and a general greening of the planet. 

See here and here.  Satellites show that in the period 1982-2011, 31 per cent of Earth’s vegetated area became more green, 3 per cent more brown. The main reason: carbon dioxide.

Leave the last word to Professor Judith Curry, of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, who used to be alarmed and no longer is. Her message to the IPCC this week was: “Once you sort out the uncertainty in climate sensitivity estimates and fix your climate models, let us know .. .. . And let us know if you come up with any solutions to this ‘problem’ that aren’t worse than the potential problem itself.”

Matt Ridley, a member of the British House of Lords, an acclaimed author who blogs at www.rationaloptimist.com. This article was first published in the Wall Street Journal.