Last night (Feb 25th) I did a question time event at Leicester Grammar School in Great Glen with inter alia Eric Goodyer (him of the Gatling Gun delivery), Labour candidate for Charnwood (good luck, Eric — you’re gonna need it!), and Green activist and former euro-candidate Sue Mallender. At one point, speaking about proportional representation, Sue said “a green vote is never a wasted vote”. But last June she demonstrated the opposite. Some thousands of votes were cast in the euro elections in the East Midlands for her Green Party list, yet no Green was elected, so every one of those votes was wasted. The idea that proportional representation means “no wasted votes” is a nonsense.
Inevitably, the climate question came up. Sue trotted out the “overwhelming scientific consensus”, while admitting that “one or two scientists” might disagree. I pointed out that tens of thousands disagreed, including IPCC panellists; that hundreds of prominent sceptical scientists would gather in Chicago in May for the Heartland Conference, and that I looked forward to meeting them; that since the CRU and IPCC scandals broke, more and more scientists have been emboldened to come out of the woodwork and voice sceptical opinions; and that the Amazon non-fiction list features a raft of sceptical books on climate (I’m reading “The Hockey Stick Illusion” by Montford at the moment).
Eric Goodyer, an uncritical believer in all modish fads like the EU and climate change, tried to take an authoritative tack. He was a scientist. He knew all about it. CO2 was a greenhouse gas. It blocked a significant segment of the infra-red spectrum. This was trapping heat in the atmosphere and causing warming. QED.
Sadly he doesn’t know quite enough about it. Yes, atmospheric CO2 blocks a segment of the infrared spectrum (two segments, in fact, as it happens). But what Eric didn’t know (or wasn’t going to tell us) was that it can’t block the rest of the spectrum, and that at current levels (around 390 ppm), CO2 is already blocking virtually all outgoing infra-red radiation in those two segments. Higher concentrations of CO2 will therefore make little or no difference.
The equation governing the “climate forcing effect” (greenhouse effect) of atmospheric CO2, as I have written so often, is well-understood, and is logarithmic. The curve flattens out. It is a law of diminishing returns. And we’re already so far up the curve that further increases in CO2 will have little effect.
So Eric might like to reflect on that. He also might like to reflect that global temperatures were warmer than today’s a thousand years ago, in the Mediaeval Warm Period. And two thousand years ago, in the Roman Optimum. And 5000 years ago, in the Holocene maxima. And on none of these occasions did we witness any “tipping point”, or any “runaway greenhouse effect”. On the contrary, they formed part of well-understood, long-term, natural climate cycles — as does our present climate. Eric may also like to recall that while the current CO2 level is somewhat higher than we believe it has been for some thousands of years, it is actually rather low by geo-historical standards. CO2 levels in the atmosphere have been more than ten times as high in the past. And was there runaway global warming? There was not. In fact, there was one of the biggest Ice Ages the world has ever seen.