Wealthier countries 'outsource' their carbon emissions to developing nations, a new study finds

When it comes to counting the United States' carbon emissions, we shouldn't stop at the border, say two Stanford scientists. It would be more accurate to include the carbon emitted from the factories in foreign lands that manufacture the goods we import.

Smoke stacks

The researchers found that the products imported by the developed countries of western Europe, Japan and the United States cause substantial emissions in other countries, especially China.

Photo: ©hicagoenergy, Creative Commons/Flickr

A new study shows that many of the world's wealthiest countries may in fact be responsible for much higher carbon emission rates than previous reports have indicated: By exporting their production needs to developing countries, researchers say, the United States, Japan and many Western European nations have managed to "outsource" more than half of their carbon dioxide emissions and evade responsibility for their share of the climate-altering pollution.

"Instead of looking at carbon dioxide emissions only in terms of what is released inside our borders, we also looked at the amount of carbon dioxide released during the production of the things that we consume," explained co-author Ken Caldeira, an associate professor, by courtesy, of environmental earth system science at Stanford and staff scientist at the Carnegie Institution's Department of Global Ecology.

Caldeira, along with Steven Davis, a doctoral candidate in the Department of Geological and Environmental Sciences and a research associate at Carnegie, used trade data published in 2004 to create a global model showing the flow of products from 57 industry sectors and 113 countries or regions.

By allocating carbon emissions to particular products and sources, the researchers were able to calculate the net emissions "imported" or "exported" by specific countries.

More than a third of the carbon dioxide emissions linked to goods and services consumed in many European countries actually occurred elsewhere, the researchers found. In Switzerland and several other small countries, outsourced emissions exceeded the amount of carbon dioxide emitted within national borders.

"Just like the electricity that you use in your home probably causes CO2 emissions at a coal-burning power plant somewhere else, we found that the products imported by the developed countries of Western Europe, Japan and the United States cause substantial emissions in other countries, especially China," Davis said. "On the flip side, nearly a quarter of the emissions produced in China are ultimately exported."

The United States is both a major importer and a major exporter of emissions embodied in trade. The net result is that the U.S. outsources about 11 percent (about 2.4 tons per person annually) of total consumption-based emissions, primarily to the developing world.

The researchers point out that regional climate policy needs to take into account emissions embodied in trade, not just domestic emissions.

"Our analysis of the carbon dioxide emissions associated with consumption in each country just states the facts," said Caldeira. "This could be taken into consideration when developing emissions targets for these countries, but that's a decision for policymakers. One implication of emissions outsourcing is that a lot of the consumer products that we think of as being relatively carbon-free may in fact be associated with significant carbon dioxide emissions."

"Where CO2 emissions occur doesn't matter to the climate system," added Davis. "Effective policy must have global scope. To the extent that constraints on developing countries' emissions are the major impediment to effective international climate policy, allocating responsibility for some portion of these emissions to final consumers elsewhere may represent an opportunity for compromise."

The report, "Consumption-Based Accounting of CO2 Emissions," was published online before print March 8, 2010, in the Proceedings of the National Academy of Sciences.