News release: "It is difficult to measure accurately each nationís contribution of carbon dioxide to the Earthís atmosphere. Carbon is extracted out of the ground as coal, gas, and oil, and these fuels are often exported to other countries where they are burned to generate the energy that is used to make products. In turn, these products may be traded to still other countries where they are consumed. A team led by Carnegieís Steven Davis, and including Ken Caldeira, tracked and quantified this supply chain of global carbon dioxide emissions... Traditionally, the carbon dioxide emitted by burning fossil fuels is attributed to the country where the fuels were burned. But until now, there has not yet been a full accounting of emissions taking into consideration the entire supply chain, from where fuels originate all the way to where products made using the fuels are ultimately consumed...They found that regulating the fossil fuels extracted in China, the US, the Middle East, Russia, Canada, Australia, India, and Norway would cover 67% of global carbon dioxide emissions. The incentive to participate would be the threat of missing out on revenues from carbon-linked tariffs imposed further down the supply chain. Incorporating gross domestic product into these analyses highlights which countriesí economies are most reliant on domestic resources of fossil energy and which economies are most dependent on traded fuels. To look at the data, visit here."