What's the deal with McKinsey & Co.? How much impact do its reports have? Do they get passed around corporate boardrooms? Ignored? I ask because I enjoyed this latest report, which argues that the United States could cut its greenhouse-gas emissions nearly one-third by 2030 at little cost, using mainly "tested approaches" and a few "high-potential emerging technologies." All we'd really need, it seems, is a modest carbon tax, some federal spending for infrastructure, a bunch of regulations, and, um, we're off. Yes, the Stern Review and the IPCC have said much the same thing, but maybe McKinsey can woo a broader audience.

Interestingly, about 40 percent of the mitigation measures that McKinsey studied—especially the ones that involve boosting efficiency—would actually save the country money in the medium run. The trick is to implement them sooner rather than later, since every year of delay means another round of inefficient cars and homes getting built. Conveniently enough, there's another new report out finding that California's strict efficiency rules haven't hurt the state's economy much at all. Instead, they've lowered energy costs for businesses and residents. I know, I know, who could've ever predicted that...

The McKinsey report was funded, in part, by PG&E and Shell. What this means, I can't say, though I will say that some of its conclusions sound odd. For instance, check out the graph that Dave Roberts highlights here. Is building a new nuke plant really cheaper than onshore wind and distributed PV solar? Even once all costs—waste disposal, insurance—are factored in? I'm also not sure how much hope we should hold out for carbon sequestration (though, note, that hardy perennial plays only a small role in McKinsey's vision). Also, even if mitigating climate change won't damage the U.S. economy much—and could even boost it—certain stakeholders will still get screwed during the transition. But, hell, that's never stopped people from supporting "free" trade, so...