See Comments down arrow

Clintel Report: Scenario misuse is worse than we thought

26 Jul 2023 | Science Notes

Continuing our examination of the Clintel Report critiquing the IPCC AR6, we turn to Chapter 9, where Dutch science journalist Marcel Crok provides an excellent overview of the IPCC’s misuse of future-emission scenarios to bump up the fright meter at the expense of scientific integrity. We’ve covered the RCP8.5 scam many times ourselves including in one of our fact check videos. The problem, as Crok points out, isn’t merely that the IPCC tries to ignore the expert literature showing it is implausible. It’s that in one place the IPCC admits that RCP8.5 is a low likelihood outcome, then throughout the rest of the report treats it as very probable, highlighting RCP8.5 projections above all the others. They’re not even trying to look scientific anymore.

Crok goes over the history of IPCC scenario construction and explains that the RCP projections were actually done back-to-front. For the 2013 IPCC 5th Assessment Report they needed a set of projections of how much greenhouse gas would accumulate in the atmosphere, even though there were no economic scenarios developed that would generate plausible emissions scenarios. RCP8.5 was the extreme upper end for greenhouse gas concentrations and consequent warming, projecting between 3 and 4 degree C temperature increase in just 80 years, compared to about 1 degree C over the past 170 years. But how would you get enough greenhouse gas emissions to justify that projection?

Well, for AR6, the IPCC backfilled the RCP outcomes with economic and emission projections called “Shared Socioeconomic Pathways” or SSPs that indicate what changes in human activity need to happen for the related RCP outcome to take place. Including that to get RCP8.5-level warming by 2100 would require CO2 levels in the atmosphere to rise by 150% over the next 80 years, compared to the 50% they went up over the past 170 years. And to get that big an increase would require, among other things, building 33,000 new coal-fired power plants by 2100, more than five times the current number operating globally.

You don’t need to be an expert energy analyst to know that much coal development is simply not going to happen. Most jurisdictions are actually moving away from coal, not accelerating their use of it. Besides which, the devastation predicted under RCP8.5 would reduce economic activity dramatically, preventing any huge increase in power generation. RCP8.5 saws off the branch it sits on.

A few climate experts have published papers charting the numbers and looking at realistic extrapolations and making it clear in terms even the IPCC could understand, if it wanted to, that the RCP8.5 scenario is bonkers and should never be used for anything remotely related to climate policy. And the IPCC even mentions some of this work (though conveniently ignores much of it) while quietly admitting on page 238 of the Working Group I report that “However, the likelihood of high emission scenarios such as RCP8.5 or SSP5-8.5 is considered low in light of recent developments in the energy sector.”

Whereupon they proceed to wallow in RCP8.5-based studies. As Crok notes, summarizing earlier work by Roger Pielke Jr., the IPCC makes over 3,000 mentions of climate impacts studies, of which nearly half (42%) are RCP8.5 and its related SSPs, while adding in the next most-implausible study the total rises to 53%. Crok then discusses some of the detailed analyses in peer-reviewed journals debunking the RCP8.5 scare story that failed to rate a mention in the IPCC report.

Finally, he discusses efforts by some scientists to identify what the most plausible scenario might be. The one currently tracking reality the best is called SSP3.4 which you probably haven’t heard of, and for good reason at least as the IPCC defines that term: SSP3.4 isn’t mentioned even once in AR6.

It’s hardly surprising. Any time scientific evidence throws cold water on climate alarmism, the last people who will tell you about it are the IPCC, a body that presents itself as neutral, dispassionate and fair-minded but whose existence, salaries and prestige depend on hyping the climate crisis. Which is why we’re grateful for groups like Clintel and for the many readers who support CDN so we can do what the IPCC should be doing but isn’t.

Leave a Reply

Your email address will not be published. Required fields are marked *