One other spherical of anti-science from the IPCC – with that?


August 15, 2021 / Francis Menton

With the ongoing disaster in Afghanistan and the earthquake in Haiti, among others, you may have overlooked the fact that the IPCC released substantial parts of its long-awaited Sixth Assessment Report on the state of the world climate on Monday. This is the first such assessment by the IPCC since 2014. The most important part is the so-called “Summary for Policymakers” (SPM), a 41-page section that is the only part anyone will ever read.

The IPCC tries to put itself under the guise of “science,” but its real mission is to try to scare the Bejeezus out of everyone in order to get the world to give more power to the UN. Beginning with its third assessment in 2001, the IPCC’s leading technique for creating fear was the iconic “hockey stick” graphic, allegedly showing that world temperatures have suddenly risen dramatically over the past 100 years or so, ostensibly due to human influences . In the third assessment report in 2001, the famous hockey stick diagram, which comes from the work of Michael Mann and other authors, was prominently highlighted. Here is the graph from the 2001 report:

As long-time readers here know, the hockey stick was then torn down by the work of Canadian mathematician Stephen McIntyre through his work on his Climate Audit website. The main problem was that the temperature “proxies” used to make the “shaft” of the hockey stick, particularly various series of tree rings, could not have a close relationship with actual temperatures; In addition, there were strong reasons, from many sources, to believe that the Medieval Warm Period (around AD 1000-1300) was warmer than the present.

And then came the ClimateGate emails from 2009. From my post on February 22, 2018:

The coup de grace for the hockey stick graph came with the so-called Climategate emails published in 2009. These were emails between and among many of the main promoters of the climate catastrophe (called the “hockey team” by McIntyre). Climategate’s publications included emails specifically related to the methodology used to create the chart. Skeptical researchers come from the emails. . . discovered that The graph creators had truncated inconvenient data to get the desired representation.

One particular series that went into the development of the hockey stick came from a guy named Keith Briffa. Briffa’s series was very different from actual temperatures and declined (decreased) significantly after about 1960 when temperatures measured by thermometers increased. This fact had to be kept secret in order to keep the hockey stick presentation going. So the makers simply deleted the inconvenient information. The most famous of the ClimateGate emails copied among various Hockey-Stick participants (including Mann) dated November 16, 1999 described the situation as follows:

I just finished Mike’s Nature Trick which adds the real temps to each series for the past 20 years (i.e., from 1981) and from 1961 to hide the decline.

In any rational world, that email alone would have ended the careers of all these participants. In the real world we live in, Mann continues to hold a prestigious position at Penn State University and won the AAAS award for Public Engagement With Science in February 2018.

And with this in mind, we come to this week’s SPM. After some prep, here’s the big scary headline:

Human influence has warmed the climate at a rate unprecedented for at least the last 2000 years

And to prove it? Yes it’s another hockey stick diagram. Although it comes from different authors and apparently different data, it shows a striking resemblance to the graph by Mann et al. from 2001 on.

McIntyre is back in action promptly. Here is his post from Aug. 11, where he basically dismantles the new hockey stick. If you have a taste for many technical details, I recommend that you read the whole thing. But the main thing is actually simple. This time, these people would not be secretly caught “hiding the decline.” Instead, they boldly announce that they will simply exclude any data that does not fit the narrative they have put forward.

McIntyre goes through several of the series of data that contribute to the “shaft” of the new stick. Most seem to be just random swings up and down. But then there are the few key series that show the sharp twentieth century surge that is required to support the hockey stick narrative. One such series is the McKenzie Delta tree ring series by Porter et al. from 2013. McIntyre goes back to this Porter article and cites the passage describing how the researchers selected the trees that would add to the series:

Understood? It is a “divergence-free chronology”. You can do this by simply excluding any data that does not match the desired result. And you don’t even have to exclude entire trees from the series, just the parts of a particular tree that just don’t seem to fit.

McIntyre Comments:

They took “hiding the decline” to extremes never considered by previous practitioners of this dark art. Instead of hiding the decline in the end product, they did this for individual trees: As explained in the underlying article, they excluded the “divergent proportions” of individual trees that have dared to decline in growth in recent years. Even Briffa would never have thought of such radical measures.

Read the full article here.


Item rating

Like this:

Like Loading…

Comments are closed.