As the risks of climate change and the difficulty of effectively reducing greenhouse gas emissions become increasingly obvious, potential geoengineering solutions are widely discussed. For example, in a recent report, Blackstock et al. explore the feasibility, potential impact, and dangers of shortwave climate engineering, which aims to reduce the incoming solar radiation and thereby reduce climate warming. Proposed geoengineering solutions tend to be controversial among climate scientists and attract considerable media attention. However, by focusing on limiting warming, the debate creates a false sense of certainty and downplays the impacts of geoengineering solutions.
So begins, “Risks of Climate Engineering” (subs. req’d), an important piece in Science this month by Gabriele Hegerl and Susan Solomon. Hegerl was a coordinating lead author for the Fourth Assessment Report. Solomon is an atmospheric chemist working for NOAA and “one of the first to propose CFCs as the cause of the Antarctic ozone hole.”
Solomon was lead author of the even more important February PNAS paper, “Irreversible climate change due to carbon dioxide emissions,” which, as I noted at the time, gives the lie to the notion that it is a moral choice not to do everything humanly possible to prevent this tragedy, a lie to the notion that we can “adapt” to climate change, unless by “adapt” you mean “force the next 50 generations to endure endless misery because we were too damn greedy to give up 0.1% of our GDP each year” (see NOAA stunner: Climate change “largely irreversible for 1000 years,” with permanent Dust Bowls in Southwest and around the globe). No surprise, then, that she co-authored a paper skeptical of geoengineering.
I remain dubious of geo-engineering (see Geo-engineering remains a bad idea” and “Geo-Engineering is NOT the Answer” and British coal industry flack pushes geo-engineering “ploy” to give politicians “viable reason to do nothing” about global warming, which includes an excellent analysis by Prof. Alan Robock). Science advisor John Holdren told me in April that he stands by his critique:
“The ‘geo-engineering’ approaches considered so far appear to be afflicted with some combination of high costs, low leverage, and a high likelihood of serious side effects.”
The new analysis by Hegerl and Solomon is sufficiently significant — Science itself featured it early in Science Express — that I’ll excerpt it below: