A copy of the much anticipated US Senate climate bill reveleas a proposal that calls for a  cut in  US greenhouse gas emissions of 20 percent from 2005 levels by 2020 – a more ambitious cut than the House bill from June, which called for a 17 percent cut over the same period.

The House and Senate bills both include a long-term target of an 83 percent reduction by 2050.

Proposed by California Democrat Barbara Boxer, who heads the Senate Committee on Environment and Public Works, and Sen. John Kerry (D., Mass), chairman of the Senate Foreign Relations Committee, the legislation will be debated in the Senate starting the end of October.

Differences in the Senate and House bills, aside from the Senate’s high ambition:

-  Unlike the House bill, the Senate proposal does not spell out how the government plans to allocate billions of dollars worth of permits to emit greenhouse gases.

- Unlike the House bill, the Senate’s draft bill would preserve the authority of the Environmental Protection Agency (EPA) to use the Clean Air Act to regulate greenhouse gases. Because that law generally gives the EPA limited flexibility to consider costs when setting regulations, some business groups and many lawmakers fear the agency’s regulation of greenhouse gases could lead to onerous, new rules on business.

- The Senate bill  includes provisions to fund training of workers in the nuclear industry and development of technology that could reduce emissions from coal-fired power plants.