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 Delingpoleâs wrongness is the usual kind of stuff that will make the rounds of the deny-o-sphere, so Iâll 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 IPCCâs 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 IPCCâs prediction range. The computer models, in short, are bunk.
Actually, no. They didnât predict ârunawayâ 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 ârunawayâ. Delingpoleâs use of the term is a strawman.
Next, the real rise in temperatures has not fallen outside âthe lowest parametersâ (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.
Itâs true that temperatures have flattened out over the past decade or so, but this doesnât mean global warming has stopped, that weâre cooling, or the models need to be thrown out. Quite the opposite, which Iâll show in a moment.
And finally, no, the models arenât âbunkâ. In fact the models are doing a pretty good job of representing the physical nature of whatâs going on. The real problem isnât with the models, itâs with people interpreting them, or, more accurately, misinterpreting them. Again, Iâll cover this below.
This is why the latest Assessment Report is proving such a headache to the IPCC. Itâs the first in its history to admit what its critics have said for years: global warming did âpauseâ unexpectedly in 1998 and shows no sign of resuming. And, other than an ad hoc new theory about the missing heat having been absorbed by the deep ocean, it cannot come up with a convincing explanation why.
Well, actually, no. Thatâs like seeing a corpse with a bullet wound to the head and saying âExcept for the bullet wound to the head you cannot come up with a convincing explanation why this person is dead.â
The idea that the missing heat is being absorbed by the deep ocean is hardly ad hoc. Itâs observed. And itâs hardly ânewâ; weâve known the deep ocean has been heating up for a while. This is also happening at the same time that weâre seeing relatively cooler surface temperatures in the Pacific ocean, which cools the air. Thatâs part of a natural cycle, with ocean surface temperatures going up and down over time. For the moment, that effect is greater than the overall warming trend of surface temperatures, so we see a flattening. And despite Delingpole simply dismissing this idea, recent computer models which incorporate the cooler Pacific waters have been able to reproduce this temperature flattening effect pretty well, too (shown in the inset graph), strengthening our understand of how the ocean affects land surface temperatures.
When we cycle back into warmer surface temperatures, the land surface temperature will go back up. Weâve seen this happen before, over and again in the past. You have to be careful not to make any long-term claims about that either; scientists are careful to average over both cooler and warmer cycles to look at the overall trend. Denialists love short-term trends, because they can cherry-pick them to make it look like temperatures are stable or even dropping, when in reality the overall trend is up, up, up.
So the computer models arenât âbunkâ, as Delingpole claims. Theyâre pretty good, and our best bet for figuring out whatâs going on. They get better at doing so over time, too.
This latest report is hardly a âheadacheâ for the IPCC, but since theyâre ramping up the rhetoric so much itâs obviously a thorn in the side of deniers. Who, I suppose, are a headache for the IPCC.
And Iâll remind you that while denialists are distracting everyone about the âpauseâ, about climate sensitivity, and all that, the Arctic sea ice is melting. Antarctic land ice is melting. We just experienced the hottest decade on record. And itâs difficult to stress this enough: The trend over time is higher temperatures.
I could go on; Delingpoleâs article is a rich source of the same tiresome anti-reality claims. But as usual, when you dig even a tiny bit into things like this, the denials fall apart. I suggest you keep your browsers pointed to locations of good information, like Skeptical Science, Dana Nuccitelli and John Abrahamâs column called âClimate Consensus-the 97%â in The Guardian, and follow real climate scientist Michael Mann on Twitter.
And not that Iâm looking forward to this, but eventually the ocean cycle will switch back to warming, and land surface temperatures will once again begin their inexorable climb. What will the deniers say then? I can guess: Theyâll forget all about this âpauseâ, and focus on some other cherry-picked event to muddy the waters. They are as predictable as, well, the climate.
Tip oâ the thermometer to Brandon Rhea on Twitter.