Ask the Expert: Andrew Light on carbon cap equivalents and global emission reduction goals

What are carbon cap equivalents?

Carbon cap equivalents are an alternative way of measuring a country's emissions reductions. Rather than only just counting, say, economy-wide measures like a cap-and-trade program or a carbon tax, to determine how many tons of carbon a country can commit to reducing in terms of its emissions, it counts complementary policies such as provisions for decreasing emissions through aid to international forestry programs.

How do carbon cap equivalents change thinking on U.S. emissions reduction efforts?

Currently, the Untied States is proposing to reduce its emissions 17 percent below 2005 levels by 2020. When you compare this to what other countries are doing, the U.S. contribution is pretty small. It only amounts to, really, 1 percent of reductions below 1990 levels by 2020. If we look at the U.S. contribution not only in terms of its economy-wide measure, the cap and trade program that's been proposed through the House legislation, and we count on the other provisions that they're willing to do, then, in fact, their decreases in emissions go to something like 13 percent below 1990 levels by 2020, and as much as 21 percent below 1990 levels by 2020. Measured in this way, the U.S. actually meets the reductions its allied are doing in terms of emissions reductions, rather than falling far below them as it's accused of doing now.

How achievable are global emission reduction goals?

The global goal in terms of reducing emissions as set by the Intergovernmental on Climate Change, is to cut global emissions by half by 2050. It's believed that if we do this, then we'll hold any increases in temperature to 2 degrees Celsius above pre-industrial levels. The contribution of developed countries to this goal is to cut emissions by 80 percent below 1990 levels by 2020. If we take a comprehensive measure, as CAP has done, of what all the developed countries and what all the major emitters in the developing world such as China, India, Brazil, South Africa, and Indonesia are doing, then it looks like, if everyone does what they say they are going to do, we will achieve 65 percent of reductions needed to hit this global goal and hold temperature rise to 2 degrees above pre-industrial levels.