The Gift That Keeps on Giving

Edit: Several days ago, I accidentally uploaded this post as a new page in the toolbar above instead of as a post. I've deleted that page and am now reposting it as a blog post.


Because my last post commented on some silliness over at blogger Anders's place, I've been looking at his site from time to time. I'm happy I did because his latest post is hilarious. I'm not going to give any background on the controversy being covered. People who want to know about it can read the post and check his links. Instead, I'm just going to post a couple excerpts which are "classic":

A while ago Judith Curry wrote a rather confusing post about the IPCC’s attribution statement (that more than 50% of the warming since 1950 was anthropogenic). Gavin Schmidt responded on RealClimate, and Judith Curry has been promising to respond to Gavin’s article for quite some time. Well, the response is now here and it is a classic. It appears to be related to there being some confusion regarding the meanings of the terms most, more than half, and > 50%.

I’m slightly surprised that Judith is confused by these terms, so I thought I would parse the IPCC statement to try and help. The IPCC attribution statement in question is below, and I’ve inserted bolded bits to try and explain the terms in question:

It is extremely likely (in IPCC speak, this means more than 95% probability) that more than half (this means > 50%) of the observed increase in global average surface temperature from 1951 to 2010 (this is the thing that the other thing is more than half of) was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together (us). The best estimate of the human induced contribution to warming is similar to the observed warming over this period (we probably contributed most).

That is how Anders's post begins. A commenter quickly pointed out:

Actually I think that was NOT what was meant by “most” and you’ve confused things a bit up in the top article by using “most” to mean “around 100%”.

After which Anders made comments saying things like:

Yes, I think you’re probably right.

Maybe, I should have thought a bit more about the term most.

I realise now, that I hadn’t appreciated that the most came from AR4, and was really the AR4 equivalent of more than half in AR5. Teach me to focus more on getting the spinal tap video in at the end, than on the post itself 🙂

Yes, given that I managed to stuff up most here, I’ll grant you that.

And when a person said:

She is almost certainly not (and it would be uncharitable to interpret her as) saying that the observed warming could be 220% of the observed warming, in which case the contribution of 110% of the observed warming does not contribute more than 50% of the observed warming (which is, however, how you have interpreted her).

He responded:

Maybe I am being uncharitable, but it seemed such an odd response to my tweet, that I couldn’t really help myself.

I get Anders is "slightly surprised that Judith is confused by these terms." It is quite nice of him to "parse the IPCC statement to try and help."

I just can't help but notice Anders seems to have been quite confused himself.

One comment

  1. As usual, Anders makes a claim and, when challenged, says that he is being misunderstood. He must be the most misunderstood person in the blogosphere. Either that or he is merely running a site for abusive morons such as BBD, Verytallguy, Anoilman, and Steve Bloom to congratulate each other on their intelligence and abuse people with other points of view.

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