Waste of Time

I've been having a hard time finding things to talk about recently. The global warming discussion has gotten incredibly stale for me so I wanted to branch out and look at other things. However, when your focus is on how the world is insane, it's difficult to discuss anything except things involving Donald Trump. There's nothing new or interesting for me to say about him so...

quite frankly, it feels like a waste of time to talk to people. I was given a great example of this recently. I saw this retweeted by a person I follow on Twitter:

Both the person who tweeted it and the person who retweeted it are climate scientists. As such, I was baffled by seeing this. The small exchange which followed shows the futility of trying to have a discussion.

The paper mentioned in that tweet says in its first paragraph:

It is now widely accepted that it is appropriate - and necessary for decision making - to frame climate change as a problem in risk assessment and risk management (King et al, 2015; Weaver et al 2017). In the AR5 greater use was made than in previous Assessment Reports of a formal risk assessment framework which spans the dimensions of hazard, exposure and vulnerability (IPCC, 2014). However, risk framing had little influence on the WGI report, and this needs to be addressed in AR6.

The example the paper gives to demonstrate how this could be done is:

With a caption which says:

Figure 1: A schematic representation of how climate change risk depends on equilibrium climate sensitivity (ECS). Panel a shows a possible likelihood distribution consistent with the IPCC AR5 assessment that “Equilibrium climate sensitivity is likely in the range 1.5 C 10 to 4.5 C (high confidence), extremely unlikely less than 1 C (high confidence) and very unlikely greater than 6 C (medium confidence).” Panel b illustrates schematically the fact that the cost of impacts and adaptation rises very rapidly (shown here as an exponential damage function) with ECS. Panel c shows that, in this example, the resultant risk (quantified here as likelihood x impact) is highest for high ECS values. The precise shape of the risk curve is dependent on assumptions about the shape of the likelihood and damage functions at high sensitivity (Weitzman et al, 2011). (Figure by Ed Hawkins.)

(Ed Hawkins, credited for the figure, is also the person whose tweet was shown earlier in this post.)

A casual reader might think this figure is intended to show something at least somewhat representative of the current state of knowledge of the scientific community. That would be wrong. Pay attention to the terminology used in this caption, "Panel a shows a possible likelihood distribution consistent with the IPCC AR5 assessment..." While it is perhaps true that depiction is "consistent with" what the IPCC has said, it is in no way supported by what the IPCC has said. The IPCC acknowledges we don't know what the shape in the first panel is in reality, meaning a person can draw almost anything they want (as long as it meets a couple simple requirements) and it will be "consistent with" what the IPCC has said.

An obvious question then, is this. How could the IPCC ever hope to use this approach in its reports if it couldn't say what the shape in that first panel is? This approach effectively just multiples the curves in the first two panels to generate the curve in the third panel. If you don't know what one (or both) of the curves is, the approach can't work. This led me to respond to the tweet asking for feedback by saying:

PDF stands for probability density function, a curve which shows the likelihood of a continuum of possibilities like seen in the first panel. According to the latest IPCC report, we don't know what the curve (PDF) is for climate sensitivity. That report is several years old though so it's possible the IPCC would reach a different conclusion in the next report. Noting this, I responded to the person who had retweeted the post:

This seems like a trivial point which should raise no controversy. For this suggested approach to work, you need to have a PDF for climate sensitivity to work with. According to the latest IPCC report, we can't come up with one. Therefore, the approach won't work. That is where things stand, at least in terms of the latest IPCC report.

Confronted with a situation where the IPCC's most recent position is we don't have the knowledge to make it possible to use an approach, anyone recommend the IPCC use that approach ought to explain how the IPCC could overcome that obstacle. This paper doesn't. In fact, this paper doesn't even acknowledge the IPCC's position on the matter. Nobody reading the paper would see anything to indicate the IPCC says we don't know what the PDF of climate sensitivity is.

In fact, apparently even knowledgeable climate scientists reading the paper are left unaware of such a crucial detail, being forced to ask:

It is incredible a climate scientist would need me, a random schmuck on the internet, to tell him where the IPCC made one of the most crucial points in its report. It's even more incredible when you consider his remark about the IPCC showing PDFs of TCR.

Now, the climate sensitivity which was being discussed (and shown in the paper) is ECS, basically a long-term climate sensitivity. TCR is basically a shorter-term sensitivity. Both are important for their own reasons, but the paper was clearly quoting the IPCC report about ECS not TCR. Additionally, the PDFs he referred to were not PDFs the IPCC report offered as a conclusion. Instead, they were PDFs from individual studies that have been published. Here is Figure 10.20 of the AR5 WG1:

It's clear the IPCC felt it could show PDFs generated by various researchers whose studies were examined by the IPCC. Not only did it show PDFs for TCR like Richard Betts said, it also showed PDFs for ECS. This tells us nothing about the issue I raised though. A central issue for the IPCC was how to compare and contrast these various studies, their methodologies and their results to come up with a conclusion which reflected the "consensus" view of the scientific community.

It's well worth reading the discussion in Chapter 10 of this issue, but Twitter isn't the place for such things so I went with the obvious quote from the IPCC's summary of the report and then addressed what Betts said about the PDFs shown by the IPCC:

Betts didn't question me further about what the IPCC said further so I assume he acknowledges what the IPCC said, instead raising this issue:

I had said nothing about the approach recommended by this paper being "impossible" in any absolute sense. My initial tweet asked if it was weird to recommend the approach given the IPCC said we don't have the information needed to use it. I then said this approach is impossible to use if we don't have that information. At the same time, I raised the possibility we could obtain that information (and that it was possible such had happened since the last IPCC report was written).

I don't think Richard Betts is stupid. I don't know why he asked me to reference a central conclusion of the latest IPCC report which he ought to be fully aware of. I don't know why he cited the existence of PDFs from individual studies in response to me saying IPCC said it was unable to create a singular PDF out of the various lines of evidence it had. I certainly don't know why Betts argued against the idea this recommended approach is impossible on even a theoretical level, something nobody had said.

What I do know is I find it obnoxious for people to behave like that. I don't know if he was feigning ignorance/stupidity. I don't know if he was intentionally misunderstaneding/misinterpreting what I wrote. I don't know if maybe he just didn't bother to try to read what I wrote, putting so little effort into our exchange that he genuinely believed what he wrote out of some form of bias. I don't know if it the explanation was something else entirely. I really don't know.

I also really don't care. Whatever the cause for this sort of behavior doesn't really matter. What matters is this is exactly the sort of thing which made me quit trying to talk to global warming advocates/climate scientists. The issue I raised was to any fair-minded individual, uncontroversial. It was a trivial point based upon a central conclusion of the latest IPCC report. I shouldn't have needed to point it out to people paid to study these issues. I certainly shouldn't have gotten any grief for doing so. But according to Betts:

This "was just a conversation." To Betts, this is just how you should respond to anyone who raises basic points any remotely competent or informed person involved in the global warming debate should understand. And if those people call that behavior obnoxious, they just have "a low tolerance." Because... apparently pointing out a person is being obnoxious means you're overly-sensitive and can't tolerate obnoxiousness... I guess?

I don't know. What I do know is as it stands, the paper in that tweet is garbage and should not be published. Any competent climate scientist should be able to see why recommending an approach which requires knowing the PDF of climate sensitivity while the (latest report of the) IPCC says we don't know that PDF is problematic.* It shouldn't take a random person on the internet pointing out the obvious for the issue to get raised. And if such a person does point out the issue, they shouldn't be forced to respond to random non-sequiturs and idiotic strawman just because a climate scientist chooses to be too lazy/stupid/ignorant/dishonest to respond to them in a legitimate manner.

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