Consumption-based accounting of CO2 emissions

Abstract

CO(2) emissions from the burning of fossil fuels are the primary cause of global warming. Much attention has been focused on the CO(2) directly emitted by each country, but relatively little attention has been paid to the amount of emissions associated with the consumption of goods and services in each country. Consumption-based accounting of CO(2) emissions differs from traditional, production-based inventories because of imports and exports of goods and services that, either directly or indirectly, involve CO(2) emissions. Here, using the latest available data, we present a global consumption-based CO(2) emissions inventory and calculations of associated consumption-based energy and carbon intensities. We find that, in 2004, 23% of global CO(2) emissions, or 6.2 gigatonnes CO(2), were traded internationally, primarily as exports from China and other emerging markets to consumers in developed countries. In some wealthy countries, including Switzerland, Sweden, Austria, the United Kingdom, and France, >30% of consumption-based emissions were imported, with net imports to many Europeans of >4 tons CO(2) per person in 2004. Net import of emissions to the United States in the same year was somewhat less: 10.8% of total consumption-based emissions and 2.4 tons CO(2) per person. In contrast, 22.5% of the emissions produced in China in 2004 were exported, on net, to consumers elsewhere. Consumption-based accounting of CO(2) emissions demonstrates the potential for international carbon leakage. Sharing responsibility for emissions among producers and consumers could facilitate international agreement on global climate policy that is now hindered by concerns over the regional and historical inequity of emissions.

Fig. 1.

Largest interregional fluxes of emissions embodied in trade (Mt CO₂ y⁻¹) from dominant net exporting countries (blue) to the dominant net importing countries (red). Fluxes to and from Western Europe are aggregated to include the United Kingdom, France, Germany, Switzerland, Italy, Spain, Luxembourg, The Netherlands, and Sweden.

Fig. 2.

Balance of CO₂ emissions embodied in imports and exports of the largest net importing/exporting countries (and Middle East region). Colors represent trade in finished goods by industry sector. Traded intermediate goods (gray) are those used by industries in the importing country to meet consumer demand for domestic goods. nec, “not elsewhere classified.”

Fig. 3.

Mean CO₂ intensity of imports and exports to and from the largest net importing/exporting countries (and Middle East region). Trade is valued at exporter prices.

Fig. 4.

Global differences between consumption (F_Cr) and production (F_Pr) emissions (i.e., the net effect of emissions embodied in trade) in 2004 by mass of CO₂ emissions in the region (Top) and also normalized per unit GDP (Middle) and per capita (Bottom). Twenty-seven countries/regions with GDP <10 G$ (1 G$ = 1 billion $US) in 2004 are excluded and appear white. Excluded countries/regions represent 155 G$ in 2004 (0.38% of world GDP), 319 million people (4.98% of global P), and 184 Mt CO₂ (0.7% of global F).

Fig. 5.

Top 10 countries/regions by net imports, net exports, and consumption emissions and bottom 10 countries/regions by consumption emissions, all presented as regional totals (Left) per unit GDP (Center) and per capita (Right). The color of bars corresponds to deciles of regional GDP per capita from the most affluent countries/regions in red to the least developed countries/regions in blue. The South Asia region aggregates Afghanistan, Bhutan, and the Maldives. The Western Africa region aggregates Benin, Burkina Faso, Cote d'Ivoire, Cape Verde, Ghana, Guinea, Guinea-Bissau, Gambia, Liberia, Mali, Mauritania, Niger, Saint Helena, Sierra Leone, and Togo. The Eastern Africa region aggregates Burundi, Comoros, Djibouti, Eritrea, Kenya, Mayotte, Reunion, Rwanda, Somalia, Sudan, and the Seychelles. The Middle East region aggregates Bahrain, Iraq, Israel, Jordan, Kuwait, Lebanon, Occupied Palestinian Territory, Oman, Qatar, Saudi Arabia, Syrian Arab Republic, the United Arab Emirates, and Yemen. The former Soviet states (FSS) region aggregates Tajikistan, Turkmenistan, and Uzbekistan (other former Soviet states are modeled separately). The East Asia region aggregates Macau, Mongolia, and the Democratic People's Republic of Korea (North Korea). The Rest of North America region (Rest N. America) aggregates Bermuda, Greenland, Saint Pierre, and Miquelon. The South Central Africa region (SC Africa) aggregates Angola and the Democratic Republic of the Congo.

Fig. 6.

Countries/regions where net exports make up the largest fraction of production emissions (Upper) and net imports make up the largest fraction of consumption emissions (Lower). The color of bars corresponds to deciles of regional GDP per capita from the most affluent countries/regions in red to the least developed countries/regions in blue. Regional aggregations of countries are defined in the legend of Fig. 5.