In Matt Ridley’s recent essay published by the GWPF, he says he needs to have 10 questions answered before he will think that policies to address global warming make any sense. I have tried to address his first three questions here here and here. Matt was kind enough to leave some comments on my second response.
Update: As the GWPF moved Mr. Ridley’s essay, I have uploaded it and you can get it by clicking here (PDF). Ridley-Lukewarmer-Ten-Tests
His fourth test is “The one trend that has been worse than expected – Arctic sea ice –is plausibly explained by black carbon (soot), not carbon dioxide. Soot from dirty diesel engines and coal-fired power stations is now reckoned to be a far greater factor in climate change than before; it is a short-lived pollutant, easily dealt with by local rather than global action. So you would need to persuade me that this finding, by explaining some recent climate change, does not further reduce the likely sensitivity of the atmosphere to carbon dioxide. Certainly, it “buys time”.
It seems to me that Mr. Ridley has indeed identified an issue that climate science is late in addressing–soot is now coming to the attention of the scientific community. It changes the albedo of ice, increasing its melt. As an aerosol, it causes more warming than thought. Scientists are now coming forth with the idea that reducing black carbon in its various forms would be a quicker way to partially address human contributions to global warming than other alternatives.
This is really good news. It may indeed serve to reduce our estimates of the sensitivity of the atmosphere to carbon dioxide. It may indeed give us additional time to find solutions to this. Andrew Revkin does a pretty good job covering this here.
I would simply ask Mr. Ridley this–does he think that having extra time is equivalent to a free pass? Does low sensitivity mean we need do nothing? If abatement of soot serves as a get out of jail free card meant to end the climate debate, would it not be wise to actually abate the soot prior to celebrating our miraculous escape from man-made global warming? Remember that soot is not the only factor involved and reducing it to zero will not halt global warming.
I do not. Reducing soot, especially in the developing world, will be expensive and time consuming. I applaud the idea of doing so and would be happy to help. But in the meantime, I think it very important for those of us in the developed world to continue our work on lowering emissions of CO2. We’ve made a good start, especially in the U.S.
So, my answer to Matthew Ridley on this point is that, sir, you are correct–but it doesn’t change what’s happening in the world nor, apart from re-prioritizing our plan of attack, does it change what we should do about it.