Samizdata

As ever, Paris was the place to see really hot models, but you have missed your chance. A couple of years ago they were basking in the admiration of the world. Now, they are looking a little old. However you can still read about them in today’s Times:

We were wrong — worst effects of climate change can be avoided, say scientists

Catastrophic impacts of climate change can still be avoided, according to scientists who have admitted they were too pessimistic about the chances of limiting global warming.

The world has warmed more slowly than had been predicted by computer models, which were “on the hot side” and overstated the impact of emissions on average temperature, research has found.

New forecasts suggest that the world has a better chance than claimed of meeting the goal set by the Paris Agreement on climate change of limiting warming to 1.5C above pre-industrial levels.

The study, published in the prestigious journal Nature Geoscience, makes clear that rapid reductions in emissions will still be required but suggests that the world has more time to make the necessary changes.

Michael Grubb, professor of international energy and climate change at University College London and one of the study’s authors, admitted that his previous prediction had been wrong.

He stated during the climate summit in Paris in December 2015: “All the evidence from the past 15 years leads me to conclude that actually delivering 1.5C is simply incompatible with democracy.”

Emphasis added. Professor Grubb was not alone. An article in New Scientist from December 2015 that included that quote from Professor Grubb also said,

And time has nearly run out for limiting warming to 2 °C. “If we wait until 2020, it will be too late,” climate scientist Kevin Anderson of the Tyndall Centre in the UK told New Scientist on Friday. “It’s a very small window.”

As for 1.5 °C, it would take nothing less than “a true world revolution”, according to Piers Forster of the University of Leeds. “We need renewable energy, nuclear power, fracking, zero-carbon transport, energy efficiency, housing changes,” he said. “Even international aviation and shipping that were excluded from this report will need to be tackled within the next few years.”

I remain more of a believer in anthropogenic climate change than many here, but after three or four cycles of this, cynicism does creep in. There is the cycle of direct prediction: DOOM BY YEAR X > two years before year X doom has failed to show any sign of arrival > DOOM BY X+10 AND WE TOTALLY HAVE GOT IT RIGHT THIS TIME. As with the lifecycle of the periodical cicada, whole theses could be written about how the the swarming and dying off of predictions of climate doom is correlated with the emergence and retreat of predictions that the only way to avoid climate doom is a globally imposed command economy. There is a long, slow rising line in which something like Professor Forster’s “true world revolution” is more and more incontrovertibly the only chance, until the date it is going to be needed to be done by becomes so close that (a) it obviously ain’t gonna happen, and (b) people start saying that if “our only chance” is something that obviously ain’t gonna happen, we might as well take our tune from the besieged citizens of Jerusalem in Isiah 22:13 and have joy and revelry, slaughtering of cattle and killing of sheep, eating of meat and drinking of wine, for tomorrow we die. At this point the trendline for true world revolution being the only solution falls off a scarp slope and the one for mere socialist austerity just possibly being enough (if we start now) starts to rise.

And that is where we find ourselves with this most recent paper in Nature Geoscience,

Speaking to The Times, he [Professor Grubb] said: “When the facts change, I change my mind, as Keynes said.

That line from Keynes has long bugged me. For every one occasion when the facts truly change there are ten where the facts are the same as ever and all that has changed is that the speaker finally had to stop running away from them. It is a phrase that sounds like open-mindedness, but in fact avoids the need to admit error. Having said that, it is better to make like slippery Keynes than to make your opinions completely impervious to reality, and Professor Grubb has done better than Keynes in that he has said he was wrong.

“It’s still likely to be very difficult to achieve these kind of changes quickly enough but we are in a better place than I thought.”

Professor Grubb said that the new assessment was good news for small island states in the Pacific, such as the Marshall Islands and Tuvalu, which could be inundated by rising seas if the average temperature rose by more than 1.5C.

“Pacific islands are less doomed than we thought,” he said.

Tuvalu’s doom level has been fluctuating since at least 2004.

Professor Grubb added that other factors also pointed to more optimism on climate change, including China reducing its growth in emissions much faster than predicted and the cost of offshore wind farms falling steeply in the UK.

He said: “We’re in the midst of an energy revolution and it’s happening faster than we thought, which makes it much more credible for governments to tighten the offer they put on the table at Paris.”

The study found that a group of computer models used by the Intergovernmental Panel on Climate Change had predicted a more rapid temperature increase than had actually occurred.

The global average temperature has risen by about 0.9C since pre-industrial times but there was a slowdown in the rate of warming for 15 years before 2014.

Myles Allen, professor of geosystem science at the University of Oxford and another author of the paper, said: “We haven’t seen that rapid acceleration in warming after 2000 that we see in the models. We haven’t seen that in the observations.”

He said that the group of about a dozen computer models, produced by government research institutes and universities around the world, had been assembled a decade ago “so it’s not that surprising that it’s starting to divert a little bit from observations”.

Here the cynic in me says that it is not that surprising in a different way that a dozen models were all wrong in the same direction. But, again, let us not be too down on Professor Grubb – at least he is partly acknowledging that scientific models are often uncertain, as Michael Jennings drew on his own experience as a research scientist to say on this blog in 2009.

He [Professor Grubb] said that too many of the models used “were on the hot side”, meaning they forecast too much warming.

See, I promised you hot models and here are so many hot models, you may even get tired of hot models.