It usually takes some effort to unpack China's various climate pledges, and this latest one is no exception. Last week, Beijing declared that the country would aim to reduce its carbon intensity by 40 to 45 percent by 2020. This doesn't mean China's overall emissions will drop, it just means that CO2 emissions per unit of GDP will decline. Because China's economy is growing at such a torrid pace, overall emissions will keep ticking upward—it's just that the rate of growth will slow. (China's pledge came shortly after Barack Obama announced that the United States would commit, at Copenhagen, to a roughly 17 percent reduction in its overall emissions by 2020.)

Now, it's important to note that China's announcement is hardly novel. They've been floating this figure for a couple of years now, and it's basically a business-as-usual course. Ideally, China would strengthen its carbon-intensity goals to 50 percent or more (which, according to many analyses, is perfectly doable). After all, for the world to have a fighting chance at preventing a 2°C temperature rise, China's absolute emissions will likely need to peak by 2020 or 2025. Yet at its current pace, the country is growing so fast that its emissions are set to double in the next two decades—even as it becomes more efficient, harnesses more renewable power, etc. China has made some very positive clean-energy moves in the past few years, but its current course probably isn't sufficient for averting drastic climate change. (Then again, from what climate science suggests, no country in the world is really doing enough at the moment...)

But the announcement isn't totally dreary. It's still a positive step—recall that just five years ago, China appeared unwilling to do anything about its emissions. Now it's starting to make concrete efforts, and those efforts have helped nudge fence-sitters on the U.S. climate bill, such as Evan Bayh and Lindsey Graham. Plus, as Charles McElwee says, an official target will force China to start measuring its own greenhouse-gas emissions more closely, and that's no minor thing. McElwee's analysis, by the way, is worth reading in full: He points out that China's new target is purely a domestic goal; they're not (yet) agreeing to this in the context of a binding global treaty and they'll likely ask for further financial assistance from the EU and the United States before getting any more ambitious.

P.S. I should also link to Michael Levi's new analysis at the Council on Foreign Relations. He smartly notes that, right now, China's essentially pledging to doing less in the next five years than it has in the previous five. There's really no reason China can't push harder.

(Flickr photo credit: