Climate Conversation Group

Professor Myles Allen -- will you ignore him?

Bishop Hill has an account — Lindzen at the Oxford Union — of the recent Oxford debate involving (mainly) Professors Richard Lindzen and Myles Allen. The latter comments (1.25pm):

“I was deeply embarrassed to be associated with Hasan’s ad hominem attacks on Dick Lindzen, in particular his going on about speaker fees and airline tickets. I thought this was going to be a discussion of climate science, and most of it seemed to be, as ever, about people and politics. As I hope I made clear when I had the chance, these were completely irrelevant to the discussion (and nothing he brought up seemed in any way exceptionable anyway) and that kind of attempt at personalising everything is just what is preventing a sensible discussion. I am very sorry that a visitor to Oxford was treated in this way.

On the science side, I’m happy to accept that studies comparing simple models with observations of the recent record, of which several have been published recently, suggest a climate sensitivity in the region of 2 degrees (although this isn’t the only line of evidence). But even a two degree sensitivity, if we do decide to burn all available fossil carbon, which would take concentrations well over 1000ppm, would be more than enough for 4+ degrees of warming. The real question, therefore, is whether 4+ degrees is OK. That’s what we need to be discussing, and unfortunately, because once again it was side-tracked onto irrelevancies, the debate didn’t go there.” (emphasis added)

Read more… »

I am sent this snippet of correspondence that refers intriguingly to continuing research into the effect of clouds on the climate. No, I won’t say who’s speaking.

Your reference to clouds led me to the work of Prof Roger Davies, who holds the Buckley-Glavish chair in Climate Physics at Auckland U.

He is part of a global group triangulating cloud data from a dedicated satellite, and seems to be developing a view that clouds provide a natural thermostat function (which Richard Lindzen has previously speculated about).

This comes from a 2008 article “Watching the Clouds” in the science faculty magazine:

Over the past eight years of data, there has been little change in the clouds over much of the Earth. However two regions stand out as exceptions. Near the equator, where the high clouds that determine the greenhouse effect are especially numerous, the cloud cover has dropped in height, suggesting a lowering of their greenhouse effect, potentially to offset global warming.

In addition, the reflectivity of the Arctic has changed. In northern summer 2006, the reflectivity of the Arctic decreased significantly, due to less cloud cover and less ice in the area, both of which reflect sunlight. However, from the ground, only a moderate decrease in ice was seen compared to its normal summer melt. The following year, there was a significantly higher ice melt than predicted, despite the fact that satellite pictures were brighter than average, and much brighter than the previous summer, due to increased cloud.

But was the 2007 melt due to the darkness of 2006? Were the clouds of 2007 compensating for the low ice reflectivity to keep a balance? Right now, we don’t know enough to say.

Interesting, but Google shows up nothing recent. He generally seems to keep his head down.

/end snippet

Tobacco/cancer comment mere malicious slur

Answers his critic as a true gentleman

See UPDATE below

I was disturbed about the comments I posted last night from a member of ‘Slick’ Hansen’s audience in Massey the previous evening. In an astonishing, unprovoked outburst, Hansen suddenly turned on the absent Dr Dick Lindzen, besmirching his character with outright lies. After trying to verify Hansen’s claim that Dr Lindzen doesn’t believe smoking causes cancer, I sent Lindzen the following email.

Dick’s reply is most thoughtfully written and I commend it for your consideration. As an outstanding example of fine thinking under personal pressure it’s a pleasure to publish it. Jim Hansen should be ashamed of himself for repeating misleading slurs and outright lies. I’m certainly ashamed of him. Read more… »