The bill could for the first time usher in widespread government restrictions on greenhouse gases and help renewable energy become cost competitive with fossil fuels.

The central part of the legislation limits the amount of carbon dioxide, the main gas behind global warming, that companies like electric utilities, gasoline refiners, chemical firms and other large users of energy can put into the atmosphere. There were previously no restrictions on carbon dioxide emissions. 

The bill aims to cut greenhouse gas emissions by over 80% by 2050, in-line with what scientists say is needed to avoid the worst effects of global warming.   

Meeting those targets is expected to cost the average household $175 a year by 2020, according to a recent analysts by the Congressional Budget Office.

Read the rest of this excellent article from CNN Money here:  http://money.cnn.com/2009/06/26/news/economy/cap_and_trade/index.htm