While voters, businesses, and politicians are calling for carbon regulation, exactly what that regulation would look like is far from decided.

Carbon taxes and cap-and-trade systems are the two most-cited proposals for cutting carbon dioxide (CO2), a major contributor to global warming. Supporters argue over which plan would be the most efficient method of cutting emissions while allowing for flexibility in the economy.

A carbon tax is a tax levied on CO2 emissions. Those who favor a carbon tax say it will drive innovations and technologies that allow for the same amount of work to be done with less pollution, and decrease the demand for products that are dirtier and thus more expensive. Critics point out that a tax would have a harsher impact on the poor, while others argue that carbon tax revenues could be used to lower other taxes, like income taxes or payroll taxes.

A carbon tax also makes many elected officials nervous: New taxes, fees, or whatever you want to call them, are rarely popular with voters. One notable supporter of carbon taxes — although he’s not running for office anymore — is Al Gore. He has promoted a carbon tax in addition to implementing a cap-and-trade program.

A cap-and-trade system requires an overall cut in emissions. Companies that cut emissions further than required are issued permits that they can then sell to companies that can’t or won’t cut emissions far enough.

Promoters of cap-and-trade say that the system provides an incentive — rather than a heavy-handed tax approach — to cut emissions because companies can sell the excess permits. It also requires a definitive limit on emissions, while some are afraid that a carbon tax would simply drive companies to pay the fines, pass the increase along to consumers, and keep on polluting. Companies like GE, DuPont, Duke Energy, and Toyota back a cap-and-trade policy, as do many environmental groups and labor unions. Presidential candidates like Hillary Clinton, John McCain, and Barack Obama also prefer it.

This fall, Congress could see a slew of measures to cut CO2. Senators Joe Lieberman (I-CT) and John Warner (R-VA) are planning to propose a cap-and-trade bill. Representative John Dingell (D-MI) is expected to introduce a carbon tax proposal — not in the hopes of actually passing it, but rather just to show how unpopular such a tax would be.

San Francisco Chronicle
Wall Street Journal, via Environmental Economics