On top of the 30% federal tax credit, there are renewable certificates that solar-power owners can sell on a market that's similar to the carbon-emissions trading market.

FORBES: Magazine Article

Proponents of carbon trading envisage a new global investment market based on emissions trading, where companies and countries have incentives to invest in developing world projects due to the highly coveted carbon credits they receive for doing so.

CNN: All About: Forests and carbon trading

Following that, 3C wants to see the creation of a global market for carbon emissions trading as well as government support for "clean" technology projects like carbon sequestration and wind farms.

FORBES: Magazine Article

Better vehicle emissions standards, reforestation and a developed carbon trading market would all help.

CNN: Trying to agree a Kyoto 2.0, as the planet simmers

The European Union argues that one credit must equal one tonne of carbon dioxide for its Emissions Trading Scheme, the largest emissions market, to be effective.

ECONOMIST: Carbon markets