Global ChangeIntersection of Nature and Culture

The hidden global CO2 emissions of consumerism

Monday, March 8th, 2010

It’s been easy for citizens of the developed, industrialized world to criticize China and India over their rapidly growing greenhouse gas emissions.  This was one of the major reasons why the Kyoto Protocol was never ratified in the United States.

As many have  pointed out, however, there are several flaws with this argument:

• The per-capita carbon emissions in China and India remain much lower (1/4 and 1/16, respectively) compared to the U.S..
• Perhaps more importantly, some of the carbon emission in these countries is caused by the production of export goods to fuel consumer demand in wealthy nations.  Thus, we are responsible for “shadow carbon emissions” that get attributed to developing nations.

Until today, there haven’t been very good estimates of these kinds of shadow emissions.

In the Early Edition of the Proceedings of the National Academy of Sciences, Steven Davies and Ken Caldeira examine how much CO₂ is embodied in the import and export of goods.¹

Their results are interesting (excerpts below—If you can get a copy of the article, check out figures 1 and 2; they are terrific visuals for this information.  Alas, copyrights don’t allow me to post them):

• Approximately 6.2 gigatonnes (Gt) of CO₂, 23% of all CO₂ emissions from fossil-fuel burning, were emitted during the production of goods that were ultimately consumed in a different country.
• Emissions imported to the United States exceed those of any other country or region, primarily embodied in machinery (91 Mt), electronics (77 Mt), motor vehicles and parts (75 Mt), chemical, rubber, and plastic products (52 Mt), unclassified manufactured products (52 Mt), wearing apparel (42 Mt), and intermediate goods (654 Mt).
• These imports are offset by considerable US exports of transport services (49 Mt CO₂), machinery (42 Mt), electronics (26 Mt), chemical, rubber, and plastics products (25 Mt), motor vehicles (22 Mt), and intermediate goods (263 Mt).
• [G]oods imported to Western Europe and Japan embody much more CO2 per US$ than do their exports, reflecting the import of energy-intensive products from elsewhere.
• The carbon intensity of imports to China, Russia, India, and the Middle East is consistently far less than that of their exports.
• China is by far the largest net exporter of emissions, followed by Russia, the Middle East, South Africa, Ukraine, and India and, to a lesser extent, Southeast Asia, Eastern Europe, and areas of South America.
• The primary net importers of emissions are the United States, Japan, the United Kingdom, Germany, France, and Italy. Although the overall mass of emissions is much less, the other countries of Western Europe are all net importers, as are New Zealand, Mexico, Singapore, and many areas of Africa and South America. Similarly, Canada, Australia, Indonesia, the Czech Republic, and Egypt are among the countries whose net exports of emissions are small.
• On a per-capita basis, net imports of emissions to the United States, Japan, and countries in Western Europe are disproportionately large, with each individual consumer associated with 2.4–10.3 tons of CO₂ emitted elsewhere.

Their conclusion:

Consumption-based accounting reveals that substantial CO₂ emissions are traded internationally and therefore not included in traditional production-based national emissions inventories. The net effect of trade is the export of emissions from China and other emerging markets to consumers in the United States, Japan, and Western Europe. In the large economies of Western Europe, net imported emissions are 20–50% of consumption emissions; the net imported emissions fall to 17.8% and 10.8% in Japan and the United States, respectively. In contrast, net exports represent 22.5% of emissions produced in China. Thus, to the extent that constraints on emissions in developing countries 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.

¹Steven J. Davis and Ken Caldeira (2010). Consumption-based accounting of CO2 emissions PNAS : 10.1073/pnas.0906974107

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Photo Credit: http://www.flickr.com/photos/deks/ / CC BY-NC 2.0