By Phil Plait
26 September 2013
(Slate) – As I predicted, with the advent of the Intergovernmental Panel on Climate Change report due tomorrow, the noise machine is out in full force.
Still, when I saw that James Delingpole had written yet another climate change denial piece for The Telegraph, I dithered. After all, in my opinion Delingpole is one of the noisiest of the deniers, saying whatever he can no matter how provocative, presumably to get a rise out of his readers. You can read all about his shenanigans at DeSmogBlog.
But The Telegraph is widely read, and Delingpole’s wrongness is the usual kind of stuff that will make the rounds of the deny-o-sphere, so I’ll stick my head in to the maelstrom momentarily.
The real meat of his column starts with this:At the heart of the problem lie the computer models which, for 25 years, have formed the basis for the IPCC’s scaremongering: they predicted runaway global warming, when the real rise in temperatures has been much more modest. So modest, indeed, that it has fallen outside the lowest parameters of the IPCC’s prediction range. The computer models, in short, are bunk.
Actually, no. They didn’t predict “runaway” warming, they use models of the atmosphere checked against real measurements to make predictions of future temperatures. The warming predicted was steady and unsettling, but hardly “runaway”. Delingpole’s use of the term is a strawman.
Next, the real rise in temperatures has not fallen outside “the lowest parameters” (he means lowest range) of the predictions. Models use different input information to predict what temperatures will be like. Some have finer time resolution, some will have better modeling of various factors, some make different assumptions than others, and so they produce different (though generally very similar) outputs. When taken together, they provide a range of predictions, and while current land and sea surface temperatures are lower than the most likely prediction, they are still within the range of predictions the models have given.
It’s true that temperatures have flattened out over the past decade or so, but this doesn’t mean global warming has stopped, that we’re cooling, or the models need to be thrown out. Quite the opposite, which I’ll show in a moment.
And finally, no, the models aren’t “bunk”. In fact the models are doing a pretty good job of representing the physical nature of what’s going on. The real problem isn’t with the models, it’s with people interpreting them, or, more accurately, misinterpreting them. Again, I’ll cover this below. [more]