Reducing soot and the other short-lived pollutants would not stop global warming, but it would buy time, perhaps a few decades, for the world to put in place more costly efforts to regulate carbon dioxide.
This notion of buying time was, in fact, the main question I had from the op-ed and which I had posed to the Climate Science Rapid Response Team. The RC post addresses it in full and argues effectively in support of its headline, that defraying action on carbon dioxide for decades amounts to
Losing time, not buying time
But in making his case, Pierrehumbert stretches Ramanathan and Victor's "perhaps a few decades" (which I take to mean two decades) to this hypothetical (my emphasis):
Let's suppose, however, that we decide to go all-out on methane, and not do anything serious about CO2 for another 30 years.
Personally, I would be more interested if his post addressed a 10-15 year window. It might also be more useful to the larger climate policy and political debate. Climate activists and establishment influentials might be inclined to get behind a change in strategy if they knew "buying time" meant a decade or so, not 30 years. Anyway (and I wrote this over at RC, as well), I doubt that Ramanathan and Victor are suggesting that carbon reduction efforts be put aside for three decades. Here's the relevant point I wanted to make, which has been said best by Andy here on a previous thread:
The fact is that political capital does not exist to implement carbon reduction policies. That simple reality can't be wished away. The goal should therefore be to build capital which, IMO, requires time and continuous effort. Incremental success on secondary and tertiary issues will help. Success in those areas will not only build political capital but will also improve the chances for some kind of carbon reduction scheme. The reason is that if you can demonstrate, for instance, that methane reduction or whatever policy is workable, then carbon reduction doesn't look so scary to people which lowers the political capital necessary to bring that about.
As I wrote at RC: It's all well and good to remind people that carbon dioxide pollution is climate enemy number one, but I think the post by Pierrehumbert (while understandably science-based) ignores one of the main rationales for focusing"“temporarily, not 30 years"“on those secondary climate forcings: It's to "buy time" while building momentum toward the necessary political conditions to tackle carbon emissions. UPDATE:
Ray Pierrehumbert responds to my comment over at RC.