E-mail to journalist David Shultz [2016-08-11]

From: D.J. Keenan

To: David Shultz

Cc: lovejoy@physics.mcgill.ca; diffenbaugh@stanford.edu

Sent: 2016-08-11 15:32

Subject: Re: Interview for the American Geophysical Union

The paper of Lovejoy et al. is based on this assertion: “Keenan claims to have used a stochastic model with some realism”. I do not make such a claim. If Lovejoy/AGU are going to assert that I do, then they should supply the source and quote.

The claim is obviously false. By asserting that I have made an obviously false claim, Lovejoy/AGU are libeling me. I am not intending to sue for libel. If AGU were concerned to act ethically, though, then it would not publish the paper of Lovejoy et al. Additionally, without the false claim, the paper has no technical basis; so if AGU were concerned about technical validity, it would not publish the paper.

I see that the paper is being published in the journal Geophysical Research Letters. The journal’s editor in chief is Noah Diffenbaugh. Diffenbaugh is also a co-author of the article “Debunking the climate hiatus” [Climatic Change, 2015]. That article is invalid, and my Contest demonstrates such. Moreover, I have previously emailed Diffenbaugh about this issue.

Lovejoy et al. also state the following.

Keenan even made a submission to the UK House of Lords on the issue of uncertainty assumptions. In order to further attract public attention, on November 18, 2015, Keenan publically proposed a “climate contest” with a $100,000 prize (http://www.informath.org/Contest1000.htm).

That is essentially correct (strictly, my critique was not submitted the UK House of Lords, but rather to the UK government). The title of my critique is this: “Statistical Analyses of Surface Temperatures in the IPCC Fifth Assessment Report”.

As the critique explains, when doing statistical analysis, the first step is to choose a model of the process that generated the data. The IPCC did indeed chose a model. I have only claimed that the model used in the Contest is more realistic than the model chosen by the IPCC. Thus, if the Contest model is unrealistic (as it is), then the IPCC model is even more unrealistic. Hence, the IPCC model should not be used. Ergo, the statistical analyses in the IPCC Assessment Report are untenable, as the critique argues.

For an illustration, consider the following. Lovejoy et al. assert that the Contest model implies a typical temperature change of 4 °C every 6400 years—which is too large to be realistic. Yet the IPCC model implies a temperature change of about 41 °C every 6400 years. (To confirm this, see Section 8 of the critique and note that 0.85*6400/133 = 41.) Thus, the IPCC model is far more unrealistic than the Contest model, according to the test advocated by Lovejoy et al. Hence, if the test advocated by Lovejoy et al. were adopted, then the IPCC statistical analyses are untenable.

The critique also discusses, at length, why no one has been able to find a realistic model; see especially Section 10. All that is ignored by the paper of Lovejoy et al. There are other problems with the paper as well.

Finally, if Lovejoy were interested in scientific truth, then presumably he would have discussed his assertions with me prior to submitting the paper to the journal.

Thanks Doug, I've read a good deal of your critique already. I'll take a closer look at section 10 tonight. Please let me know when you have a few minutes to talk after you've had chance to read the the new publication. I'll pass along the supplementary materials shortly.

My name is David Shultz and I'm a science journalist. I'm currently working on a news story for the American Geophysical Union. The article centers around a new publication by your colleague Shaun Lovejoy in which he analyzes your series of 1000 stochastic processes that emulate global climate since 1880. I was wondering if you'd had a chance to read his publication (attached here for your convenience) and if you'd like to comment on the results. I'd love to get your opinion.