In balmy Cancun, at a U.N. conference on climate change, China and the U.S. remain the elephants-in-the-room of all discussions. Both are more focused on the commercial potential of climate-related technology than on any environmental goals that could impair economic growth. Such a focus should sell better in Washington, but it’s an area where the U.S. is lagging, and China’s lead is growing.

U.S. Energy Secretary Steven Chu, speaking at the National Press Club earlier last week called China’s mounting successes in clean energy a “Sputnik moment” for the U.S.

In 1957, a refrigerator-sized sphere transmitting a steady radio signal was lofted into orbit by the Soviet Union, sparking a generation of U.S. technical and scientific discovery. But it took decades for satellite technology to become a commercial market.

Now, in clean technologies, China is racing into well-established, fast-growing markets U.S. players are eyeing hungrily. Chu named the most vulnerable areas, where the U.S. must innovate quickly, or risk falling behind…