It’s a better measure but not a perfect one. The big problem with the US-China GDP comparison is that the US has much more of a service economy while China has a much more manufacturing based economy.

Manufacturing pollutes much more than services do but services don’t exist without the manufacturing.

That’s why I was saying a better measure would be pollution per GNP. That would cut out services and basically just count manufacturing output. That would make sense because it’s the biggest source of pollution and it’s the source you can do the most about (ie there’s a lot of room to make many parts of the manufacturing chain cleaner).

Nobody is as green as their marketing suggests and China is no exception. China is making huge investments in green tech and there’s still a long way to go.