AMSTERDAM — When the panda smiles, the world applauds. Or so it seemed after Chinese President Hu Jintao's recent speech at the United Nations. Judging by the way much of the media reported his words, it seemed as if China had actually made an important announcement on cutting greenhouse-gas emissions.

It hadn't. All President Hu really said was that China would now "endeavor" to curb its carbon emissions by a "notable" margin. But how does one measure "endeavor" or "notable"?

As someone with close links to the Chinese administration told me when pressed, "What was said was actually pretty meaningless."