"One of the stickiest points in international climate change negotiations is how to account for carbon dioxide and other greenhouse gas emissions produced to make goods that are then sold for export. ...

Put another way, if manufacturing an automobile in, say, Korea, produces 10 tons of carbon dioxide  emissions and the car is then bought in the United States, which country should be considered responsible for those 10 tons? ...

Although analysts have pondered this question for years, there has been little hard data to compare carbon imports and exports. But two scientists at the Carnegie Institution for Science at Stanford University have published a new study in the Proceedings of the National Academy of Sciences (subscription required) that aims to quantify how much of each nation's carbon dioxide consumption is produced locally and how much is 'embedded' in imported goods."

John M. Broder reports for the New York Times March 8, 2010. [2]