September 29, 2008
Carbon Dioxide and the Global Economy
The figure below shows the relationship of carbon dioxide emissions from the burning of fossil fuels (with data from the U.S. Energy Information Agency) with global GDP (as measured in PPP terms and reported by Maddison).
A few things stand out.
First, the relationship between economic activity and carbon dioxide emissions is exceedingly close.
Second, from 2001 to 2006 the rate of increase of emissions per
dollar of economic activity doubled as compared to the period 1990 to
2000. This is the same change in emissions that we documented in Nature
last spring (PDF).
Third, while it is uncertain what exact effect the global economic
slowdown will have on emissions, a good bet is that emissions will
increase at a rate proportionately less. Though there is some
uncertainty due to the fact that the sowdown may manifest itself to a
greater extent in less carbon intensive sectors of the economy, such as
Finally, in 2006 the world averaged 0.62 tonnes of carbon dioxide
for each thousand dollars of economic activity. To achieve goals of
decarbonization of the global economy will require that this figure be
reduced to between 0.15 to 0.25 tonnes per thousand dollars by 2030
(depending on your target and assuming a 3.5% annual GDP at PPP growth
rate). No developed country in the world is anywhere close to achieving
this level of decarbonization and no country is remotely on a path to
meet such a goal.