More than one-third of the carbon dioxide emissions associated with consumer goods used in developed nations is actually emitted in other nations where the products are made, according to a new study. In the U.S., about 2.5 tons of carbon produced per person annually — or about 11 percent of U.S. per capita emissions — are emitted elsewhere, researchers at the Carnegie Institution for Science say. In Europe, it’s about four tons of carbon per person. In fact, in smaller European nations like Switzerland, the emissions associated with products manufactured outside the borders exceed the actual emissions produced at home.

Using 2004 trade data from 57 industry sectors and 113 countries and regions, researchers at the Carnegie Institution for Science constructed a global model of the flow of products and "imported" and "exported" greenhouse gas emissions. They found that more than one-third of carbon dioxide emissions associated with consumer goods used in developed nations are actually emitted in other nations where the products are made. The biggest "importer" by far is China.

Using 2004 trade data from 113 countries and regions, the authors of the study, published in the Proceedings of the National Academy of Sciences, were able to construct a global model of the flow of “imported” and “exported” emissions, most of which are “outsourced” to developing nations. The biggest “importer” by far is China, they said. “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,” said lead author Steven Davis.

This article originally appeared on Yale e360