When I’m trying to have a bit of a dig at physicists (of which I’m one) who think they somehow know better than climate scientists, I’ll post the cartoon on the right. When I came across this interview with William Happer, who may become Trumps’s next science advisor and who is also covered in this Guardian article, I immediately thought of it. However, I don’t think it’s quite right. The cartoon is – I think – meant to illustrate that physicists come sometimes be rather arrogant. They can think that physics is very difficult, that everything else is quite simple by comparison, and that they could step into other fields and easily solve what’s been puzzling others for ages. Happer doesn’t come across as a physicist who is just a bit arrogant; he comes across as someone who has completely forgotten how to do science altogether. A great deal of what he says is simply untrue, and demonstrably so.
For example, he says
In 1988, you could look at the predictions of warming that we would have today and we’re way below anything [NASA scientist Jim] Hansen predicted at that time.
You can look at Hansen’s 1988 paper. The prediction was that we’d warm by something between 0.4 and 1oC between the late 1980s and now. We’ve warmed by about 0.5oC. You can even plot the temperature datasets over Hansen’s predictions (H/T Nick Stokes) and it’s clear that we’re not way below anything predicted. This Hargreaves & Annan (2014) paper actually says his forecast showed significant skill. Furthermore, he considered a number of different possible future emission pathways; we’ve followed – as far as I’m aware – one closer to the middle of what he considered, so it’s not surprising that his high emission scenario forecasts more warming than has been observed. Also, his model has an ECS that is towards the high end of the range that is considered likely. Overall, his forecast is quite remarkable.
Happer continues with,
the equilibrium sensitivity, is probably around 1 degree centigrade, it’s not 3 1/2 or whatever the agreed-on number was. It may even be less. And the Earth has done the experiment with more CO2 many, many times in the past. In fact, most of the time it’s been much more CO2 than now. You know, the geological record’s completely clear on that.
Well, this is utter nonsense. The geological record is consistent with an ECS of around 3oC and is largely inconsistent with an ECS below 1oC. You can find the various climate sensitivity estimates here. We’ve already warmed by about 1oC, are only about 60% of the way towards doubling atmospheric CO2 (in terms of the change in forcing) and are still not in equilibrium. It’s utterly ridiculous to suggest that the ECS might be below 1oC. How anyone can suggest this is bizarre, let alone someone who is meant to be a highly regarded physicist.
Possibly the most bizarre thing he says (which is quite something, given all the other things he’s said) is:
I see the CO2 as good, you know. Let me be clear. I don’t think it’s a problem at all, I think it’s a good thing. It’s just incredible when people keep talking about carbon pollution when you and I are sitting here breathing out, you know, 40,000 parts per million of CO2 with every exhalation.
What’s exhaling got to do with it? The reason CO2 is accumulating is the atmosphere is because we’re digging up carbon that has be sequestered for a very long time, and burning it in a very short time; releasing CO2 into the atmosphere. Us exhaling CO2 would be entirely carbon neutral if we weren’t digging up and burning fossil fuels. Also, how can he know that it is good? This is almost entirely about risk. The more fossil fuels we burn, and the faster we do so, the more we will change the climate and the faster it will change. Can we adapt to these changes, both in terms of the magnitude and the speed? The answer may not be definitive, but there is pretty convincing evidence to suggest that continuing to emit increasing amounts of CO2 into the atmosphere may produce changes that will be very difficult to deal with. This doesn’t definitively mean that we shouldn’t do so, but suggesting that it is not going to be a problem at all, is nonsensical. There are scenarios under which parts of the planet essentially become uninhabitable.
What Happer says is so beyond anything reasonable, that I don’t think it’s fair to regard him as giving physicists a bad name. Even if physicists can sometimes be a bit arrogant, I don’t think they’re so arrogant as to say things without bothering to check that what they’re saying is actually true. It’s unbelievable that he’s being seriously considered as a science advisor. Oh, hold on, it’s for the Trump administration; I take that back, he’ll probably fit in perfectly.
Nick Stokes has a more recent post comparing Hansen’s prediction with observations and also has a post that discusses his scenarios.