SACRAMENTO, Calif. (AP) – A proposal to restructure one of California’s landmark climate change initiatives goes before a state Senate committee on Wednesday. The measure would end California’s current cap-and-trade program and impose a tax on carbon emissions. Much of the revenue would go back to taxpayers to help offset the higher bills they’d face for gas and energy. The proposal by Democratic Sen. Bob Wieckowski of Fremont is among several in the Legislature to extend the cap and trade program, which is scheduled to expire in 2020. Wednesday’s hearing steps up a legislative debate about the future of one of the state’s most closely watched programs to reduce greenhouse gas emissions. The effort faces a high hurdle, likely requiring support from two-thirds of the Assembly and Senate.