Green.view
Trading down
Industry’s move from the rich to the poor world is confusing the carbon accounts
Mar 9th 2010 | From The Economist online
ON MARCH 4th The Economist ran a story about the challenges facing scientists who are trying to find out which greenhouse gases come from where. On March 8th a paper published in the Proceedings of the National Academy of Sciences by Steve Davis and Ken Caldeira of the Carnegie Institution’s campus at Stanford University brought to the fore a further problem in trying to figure out who emits what—one that turns not on how carbon flows through the atmosphere and biosphere, but on how it flows through the world economy. Who should be held responsible for the greenhouse-gas emissions involved in making, say, a flat-screen television? The country where the television is made? Or the country where it ends up being used?
Looking at the carbon emissions associated with a country’s consumption, rather than its production, does not change the general outline of what is going on in the world: rich people still emit more carbon dioxide than poor people do. But it does heighten the contrast. Rich countries which import manufactured goods from poorer ones end up with even higher emissions; poor countries that export a lot of manufactured goods with lower ones. Using figures from 2004, the most up to date that have the sort of industry-specific data they need, Dr Davis and Dr Caldeira reveal the striking scale of this effect. They find that roughly a quarter of the world’s emissions end up being consumed somewhere other than where they are produced. For a few small and reasonably post-industrial countries, such as Switzerland, the emissions associated with total consumption (emissions produced in Switzerland minus those associated with goods produced there and subsequently exported plus those associated with goods imported) are more than twice the emissions actually produced on Swiss territory.
More generally, emissions made on their citizens’ behalf elsewhere in the world add a third or more to most European countries’ emissions. For America the effect is smaller, but still significant—about 12%. For China the situation is, obviously, reversed. Taking its exports into account reduces emissions by a quarter. In terms of emissions as usually counted, China overtook America a few years after these figures were collected, and thus became the planet’s largest source of industrial carbon dioxide; if one drops China’s total and bumps up America’s to reflect the patterns of consumption, though, America will surely remain number one for a while.
Trying to understand the scale of these flows in absolute terms is hard, but here is an illustration. It is as though more than 500 large (1,000 megawatt) power plants in China were sending all their electricity to other countries, but all their emissions still counted as Chinese.
No comments:
Post a Comment