Confession is good for the soul, and my soul is certainly in need of improvement, so here is a confession: I got it wrong in my article Geo-engineering appears in trouble, in the Advocate on Jan. 18. I couldn’t be happier about that.
The article said that a new scientific study, carried out by Angus Ferraro, Ellie Highwood and Andrew Charlton-Perez of Reading University, showed that the most widely discussed geo-engineering method for holding the global temperature down would have disastrous consequences for agriculture. The method is injecting sulphur dioxide into the stratosphere; the (unintended) result would be devastating drought in the tropics.
The idea of using sulphate aerosols in the stratosphere to reflect back some incoming sunlight, thus lowering surface temperatures on Earth, has been the leading contender for a geo-engineering solution to runaway heating since the whole subject came out of the closet eight years ago.
And then along come Ferraro et al. (as the scientists put it) to tell us that the side-effects will be disastrous. Thanks, guys.
So I ended the article by saying: “The sulphur dioxide technique was the cheapest and seemingly the best understood option for holding the temperature down. A great many people were glad that it was there, as a kind of safety net if we really don’t get our act together in time to halt the warming by less intrusive means. Now there’s no safety net.”
Almost immediately I got an email from Andy Parker, now a research fellow in the Kennedy School at Harvard University and previously a climate change policy advisor for the Royal Society in the United Kingdom. You’ve been suckered by the publicity flacks at Reading University, he said (though in kinder words). They have spun the research findings for maximum shock value. In other words, read the damn thing before you write about it.
Well, actually, I did read it (it’s available online), but the conclusions are couched in the usual science-speak, with a resolute avoidance of anything that might look like interpretation for the general public. I didn’t look long enough at the key graph that undercuts the dire conclusions of the publicists, presumably because I had already been conditioned by them to see something else there.
Drastic consequences would indeed ensue if you tried to geo-engineer a four-degrees C warmer world all the way back down to the pre-industrial average global temperature by putting sulphate aerosols in the stratosphere.
But nobody in their right mind would try to do that.
On the other hand, if you were using sulphates to hold the temperature down to plus 1.8 degrees C, in a world where the carbon dioxide content of the atmosphere would otherwise give you plus four degrees C, then the effect on tropical rainfall would be small. And that is a far likelier scenario, because we are most unlikely to resort to large-scale geo-engineering until we are right at the threshold (around plus two degrees C) of runaway warming.
So the correct conclusion to draw from Ferrero et al. is that geo-engineering with sulphates is still one of the more promising techniques for holding the temperature down, and should be investigated further. As Parker put it, “this does not tell us that we should do geo-engineering, but it does mean that the paper is a long way from being the nail in the coffin that the press release implies.”
And then I got another email, this time from my old friend Amory Lovins, co-founder and chief scientist at the Rocky Mountain Institute, who took me to task for assuming that human greenhouse gas emissions “probably will not drop” fast enough to prevent us from going into runaway warning (unless we geo-engineer) later this century.
He pointed out how strongly China is committed to clean energy. Last year, renewables (including hydro electricity) accounted for 43 per cent of new generating capacity in China, as the extra coal plants ordered long ago taper sharply down. India is showing signs of moving in the same direction, and there’s even hope that Japan may decide to replace all the nuclear capacity it is shutting down with renewables rather than coal.
So I shouldn’t be so pessimistic, they were both telling me. I believe Parker is right and I hope Lovins is right, too. But just in case Lovins is a bit off in the timing of all these turn-arounds on greenhouse gas emissions in Asia, I would still like to see a lot of research, including small-scale experiments in the open atmosphere, on the various techniques for geo-engineering.
Gwynne Dyer is an independent journalist whose articles are published in 45 countries.