'Tis the season for climate plan meta-analysis. I get asked a lot about the presidential candidates' environmental bona fides, which has led me to put together the following long, dense, and absolutely riveting primer on what to look for in a good climate change plan. These principles apply to cap-and-trade style programs, because that's what all the presidential candidates are proposing.
1. Go deep
The "cap" part of cap-and-trade refers to the emissions level mandated by the legislation. Good legislation considers both the short term and the long term.
The available science indicates we need an 80 percent reduction in greenhouse-gas emissions by 2050. For a variety of reasons (CO2 is a long-lived pollutant; the initial cuts will be easiest, etc.) we should start cutting quickly. Twenty percent by 2020 is a reasonable interim target.
Use these figures as a benchmark, but don't obsess over them. A climate change plan that calls for an 87 percent cut is not necessarily better than one calling for an 84 percent cut. Our understanding of climate change will progress over the next several decades, and we'll adjust accordingly. The important thing for now is that the planned cuts are sufficiently deep and predictable to stimulate a cascade of infrastructure improvements.