Two bills would use a portion of bond money already approved by voters to retrofit diesel trucks and heavy construction equipment with emission-control devices.160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! SACRAMENTO – Targeting truckers, contractors and others, Senate Democrats introduced legislation Thursday to reduce greenhouse-gas emissions beyond the landmark global-warming law that took effect this year. The package of bills would ban methane releases from garbage dumps; reduce exhaust emissions from trucks, construction equipment and school buses; and force utilities to increase energy from renewable sources. Other lawmakers, including some Democrats, joined Republican Gov. Arnold Schwarzenegger in immediately criticizing the legislative package. They said it would overwhelm state regulators who are still trying to decide how to implement last year’s global-warming law. That law imposes the country’s first economy-wide cap on greenhouse-gas emissions, requiring California to reduce emissions of heat-trapping gases 25 percent by 2020. But Senate President Pro Tem Don Perata, D-Oakland, said it will take state regulators too long to develop the regulations needed to achieve the mandate. Schwarzenegger wants to let companies participate in an emissions market in which they could sell, buy or trade credits. Promoting such voluntary incentives, while praiseworthy, is too slow, Perata said. “There are things we can do right now,” he said. “These bills take direct action … that will have immediate and long-term benefits.” One of the bills Thursday would require that half of passenger vehicles sold in California be able to run on alternative fuels by 2020. A second could require that a portion of diesel fuel come from renewable sources. Another would expand the renewable-energy requirement for utilities. Last year, lawmakers passed separate legislation requiring that 20 percent of power come from clean sources by 2010; the Senate proposal boosts the goal to 33 percent by 2021.