You hear all the time that China is the world’s biggest emitter. And it’s true, at least in a limited sense. What’s less obvious is this: a significant share of China’s emissions come from manufacturing products for export to wealthy countries.
On the map, the black lines indicate the transfer of the carbon-dioxide emissions that are “embedded” in trade products. For instance, you can see that 395 million metric tons of CO2 are embedded in the products China make to sell into the US market. A handful of European countries shown on the map import about three-quarters of that amount from China; and Japan imports about half as much.
The analysis, based on a global model of trade flow and using 2004 data, was performed by Steven Davis and Ken Caldeira for the Carnegie Institution for Sciences where you can read more about it. Yale’s “Environment 360” blog also has a nice write-up.