Carbon Brief has a most interesting recent article 

(no, really) about how Boris was persuaded to go for Net Zero by an eleven-slide  presentation in January 2020 organised by Patrick Vallance.

Someone called John Dodders mentioned it on Twitter, saying:

“The PM ‘bounced’ into costly & draconian decisions by a short slide show. Each slide here is debatable.”

Ben Pile retweets Dodders’ tweet and expresses doubts about something Bishop Hill says about Dodders’ point but I don’t recall the details. (Twitter is such a lousy stupid waste of time. For non-aficionados, “tweet” in bird language  means “Oh goody! I’ve found a crumb.” Trouble is, while you’re peering round to see if anyone’s heard your cheep, the crumb has disappeared in a mass of dust and feathers that makes you regret you ever opened your beak. Leave it out Ben – Also Valerius aka Maurizio, and Barry. Come back here and talk to sensible people in paragraphs of more than nineteen characters.)

Carbon Brief has obtained via the  Freedom of Information Act the eleven slides from the presentation that turned Boris from a sceptic to a fervent believer in climate catastrophe, plus the emails between those setting up the presentation. The slides are reproduced at the end of the Carbon Brief article and they have to be seen to be disbelieved. They were devised in consultation with Betts and Stott of the Met, plus a number of other people whose names have been redacted, presumably for fear of reprisals from Denialism State or something. 

Some doubt has been expressed as to whether the complexities of the climate could be encompassed in a mere eleven slides. In fact the eleven slides contain about 33 complex graphs, charts, or maps. Take for example the very first slide, which contains two graphs and two maps, namely:

2. the Keeling curve of the rise in the concentration of atmospheric CO2 since the fifties, a combination of three coloured lines label Mauna Loa, NOAA, and WDCGG. Now you and I know what Mauna Loa and NOAA mean, since we’ve been thinking of little else for the past fifteen years. We live and breathe rising CO2 concentrations, (though not on top of a Hawaiian volcano.) So does Boris, but he doesn’t know that.
4. A graph of Global mean temperature difference from 1850-1900. (That is, the difference is from 1850 to1900, not the graph, which runs up to the present.) The ever alert Boris will have noted, even if it wasn’t pointed out to him, that, after dropping half a degree from 1875 to 1910, temperatures have bounced back about 1.3 degrees in the past century, which just happens to be the most productive, beneficial century of human progress in terms of wealth, health, life expectancy or anything else you care to measure, ever. Which makes it all the more obvious why everything must be done to prevent a future rise of two tenths of a degree which would inevitably tip us over the edge of the fatal 1.5°C. Or something. This graph too has multicoloured lines labelled HadCRUT, NOAA, GISTEMP, ERA-5 etc. “Why no UAH?” I imagine Boris interjecting. Because, explains Sir Patrick with the saintly patience he was about to develop in the upcoming two years of health crisis, there were no satellites back in 1850. Nor were there computer models enabling them to retro-predict the adjustments that would necessarily have to be made to 20th century temperatures in the 21st (and no doubt succeeding) centuries. The Arrow of Time is jolly unfair sometimes. (Always, in fact.)
6. A graph of global sea level difference, showing  a steady, though slightly kinky, rise in sea levels – all the way from 1993. For some unfathomable reason (OK, fathoms are a bit last century, and not really to scale) sea level rise starts at minus 20mm (five eighths of an inch to you) which might lead the unwary to believe that back in the mists of time (the 1990s) sea levels were actually falling. It’s not mentioned that the same straight line graph could be extended backwards for a couple of centuries, to a time when gigatonnes of CO2 emissions were an industrial pipe dream and the sea was still advancing at a steady tenth of an inch per year, just like now.  

Fourthly and lastly (and apologies for the numbering of the previous three points. My new writing tool was designed by the same genius who designed the NOAA historical temperature revision app.)  on the first slide (of the eleven in the presentation) is a map of the world (Mercator projection) showing “Observed warming  2009-2019 relative to 1961-1990.” Mercator handily exaggerates our ignorance of the third of the world’s surface which is supposedly warming the fastest, and about which we know the least. But even for the rest, our knowledge seems to date from the pre-Doctor Livingstone era. Even bits of Australia are grey on the map. They can put a man on the moon and cure the common corona virus infection with horse medicine, but they can’t stick a thermometer up vast tracts of the outback.

The point is not so much whether the slides are truthful, or a fair representation of the state of the climate, but whether they are a suitable means for imparting complex information to a world leader known to have the attention span of a thirsty goldfish in search of the drinks cabinet.

That Boris’s attention may have wandered during the presentation is indicated by a remark attributed to him in the article at Carbon Brief:

“I got them [government scientists] to run through it all and, if you look at the almost vertical kink upward in the temperature graph, the anthropogenic climate change, it’s very hard to dispute. That was a very important moment for me.”

Now Betts, Stott and Vallance are fallible human beings, but they are not serial liars capable of fabricating an “almost vertical kink upward in the temperature graph.” Possibly Boris’s attention had wandered at this point, and he was gazing at an embossed pattern on the Downing Street wallpaper, or an indication of Russian troop movements up Whitehall, or an upside-down version of his popularity ratings. We all make mistakes. Not all of us make mistakes capable of plunging the population into freezing poverty, or starting world war three, or both.