Controlling Carbon Emissions

On November 10, 2010 Nature published an article updating CO2 emissions for the world. The article noted that "global CO2 emissions from fossil fuel burning decreased by 1.3% in 2009 owing to the global financial and economic crisis that started in 2008; this is half the decrease anticipated a year ago." In other words, if there is any doubt about the link between CO2 emissions and economic growth, the global financial crisis provided a natural experiment proving the link. It's very difficult (OK, impossible) to run experiments on the world system, so the result is an important finding.

The study goes on to note that once the global financial crisis is over, the economy is expected to resume growing (the IMF, here, expects the global economy to grow by 4.8% in 2010) and emitting at the same pace. The only hope for reducing carbon emissions then is to reduce the carbon intensity of the global economy, that is, quickly shift to low-carbon forms of energy (solar, wind, nuclear, etc.). To me, the shift seems unlikely (cars, buses, trucks and trains are unlikely to run on low-carbon fuel any time in the near future--even all-electric cars will run on energy from coal-fired power plants).

But, the global financial crisis may have been a blessing in disguise, at least for climate change. The time series graph above (the y-axis is CO2 emissions in PgC per year for fossil fuel burning and cement manufacturing) takes the new emission data from the Nature study and forecasts it out to 2020 assuming that the world economy grows by 4%. Although the financial bubble and collapse are clear from the data (and are predicted quite well by the model), the future growth of emission is relatively flat. Small reductions in economic growth would go a long way to stabilizing CO2 emissions. Experience with the financial bubble just might lead to more modest growth than the IMF anticipates. And, slower growth would provide some breathing room to reduce the carbon intensity of the global economy.

The Nature article also has updated analysis of the global carbon cycle. I'll analyze some of that in future posts.