A few posts down, I went through the pros and cons of the "carbon tariff" idea that's been floated by, among others, Steven Chu yesterday. The basic premise would be that if the United States passes a cap-and-trade bill on carbon, but other countries like China don't do anything about their emissions, then we could slap a border tax on select imports from those countries so as not to disadvantage our own domestic manufacturers. Anyway, here's the latest update—and brace yourselves: China's not a fan.

Earlier this evening, I was over at the Carnegie Endowment to hear Xie Zhenhua, the country's lead climate negotiator, talk about climate issues with Washington Senator Maria Cantwell, and naturally this topic came up early on. Cantwell, for one, didn't like the tariff idea at all—she's pushing to get the United States and China to agree on a bilateral energy agreement this year (that is, outside of the U.N. climate talks in December) and wanted to keep the focus on cooperation—not friction. Indeed, she's actually planning to introduce legislation to reduce trade barriers between China and the United States on exports of various green technologies.

And Xie? He looked thoroughly unamused by the whole concept: "I oppose using climate change as an excuse to practice protectionism on trade." Also, he later added, while he was open to working out various carbon-trade agreements through the WTO, this was likely to be unduly complicated and probably not the most effective way of reducing emissions. (He was responding to this proposal offered up by the Peterson Institute.)

Xie was also asked what steps he thought China would take at the Copenhagen climate negotiations this December, and replied that were three major issues at play in these ongoing talk. First, the developed countries need to put forward concrete plans to reduce their emissions by such-and-such an amount by 2020. There also need to be discussions about how the richer countries could fund clean-energy and efficiency projects in poorer countries—tech transfer is one big briar patch here (not least due to China's porous IP regime). And, after all that, the developing countries are supposed to submit ideas for reducing their carbon-dioxide emissions.

China's very much willing to cooperate, Xie said. But, he noted, China can't possibly be expected to lead the way. While the EU just set firm emissions targets for 2020, they're pretty much alone so far among the wealthy countries. Japan's not laying out its carbon roadmap until June. Meanwhile, Xie noted, "Canada has not yet issued emissions figures to meets its commitments. The United States is in the same boat—there's just talk, no action." Indeed, he wasn't really being unfair in noting that, in some ways, China's been bolder on energy policy over the past eight years than the United States has. SO now Beijing's waiting to see if Congress will actually pass a cap-and-trade bill before announcing further moves. "The key point," he repeated, "is whether Congress will pass a bill or not." Right. That's what we're all wondering.

--Bradford Plumer