The IPCC on emissions intensity

The IPCC Working Group III report – the one on mitigation and adaptation – contains some more interesting data on emissions intensity. Once again, emissions intensity is a handy concept for comparing economic efficiency, but a pointless metric for climate and emissions policy.

The report summary explains that world GHG emissions increased by 70% from 1970 to 2004, a statement widely referenced by the press. The next line of the report, not as widely referenced, explains that despite this GHG emissions increase, there was a 33% decrease in energy intensity (energy supply per $GDP) and 40% decrease in emissions intensity (emissions per $ GDP) over the same time period. As I’ve been arguing for weeks, both here and over at Worldchanging, it is important to read the IPCC summary reports yourself.

So I’ll say it again. Emissions intensity naturally decreases over time, even as total emissions increase. Setting an intensity-based target is a foolish way to reduce total emissions. And, yes, I intend to keep hammering away at this point until emissions intensity is removed from North American policy.

The above figure from the IPCC report shows that the more economically developed countries tend to have lower emissions intensity (on the y-axis). In other words, as the economy develops, it tends to become more greenhouse gas efficient. The graph also shows that emissions intensity is much higher in the US and Canada than in Japan, Australia, New Zealand and the EU. You could argue that reducing emissions should be “easier” for the US and Canada because we are less greenhouse gas efficient than other countries at a similar stage of economic development. While there is some truth to that argument, it ignores the large differences in sources of emissions in North America (e.g., large energy production) than in Europe.

What about China? Bucking the global trend, the emissions intensity in China has increased in the past decade. As the IPCC reports, the economic boom has been fueled by dramatic increases in coal and other carbon-based fuels. This is not surprising – it is just what happened in the west during the Industrial Revolution (see here). Emissions and emissions intensity rose until the early 1900s. Economic growth and emissions then began to decouple – emissions continued to soar, but the economy grew even faster.

If anything, the fact that China is bucking the global trend demonstrates the tremendous lack of leadership from western nations on this issue. Rather than learn from our experience, China is reliving it.