The U.S. Senate voted Monday to begin debate on a bill that would cap the allowable level of greenhouse gas emissions by electric power producers and other large emitters, then reduce the allowable level of emissions gradually through the year 2050.

The cap-and-trade system for carbon being proposed by the Lieberman-Warner Climate Security Act is supported by some environmental groups including the National Wildlife Federation and the Natural Resources Defense Council, but anti-nuclear groups are warning that the bill will push the U.S. to develop nuclear power.

The Nuclear Information and Resource Service and several other groups cite a statement made by a staffer from Senator Joe Lieberman’s office, who said the bill represents, “the most historic incentive for nuclear in the history of the United States.”