SACRAMENTO (AP) — A component of California’s landmark offensive against greenhouse gas emissions is not sitting well with some environmental groups.Under the measure, companies would be able to meet the state’s strict greenhouse gas restrictions in part by purchasing offsets, or credits that are generated when others achieve carbon emission reductions.Those others could be a tree planter on California’s North Coast or an Arkansas company that destroys gaseous coolants from old refrigerators.Some environmental groups are critical of offsets, saying they allow companies to get credit for greenhouse gas cuts that would have occurred anyway instead of cutting their own emissions further.“What we actually need is straightforward, meaningful reductions in emissions,” said Mark Reynolds of Citizens Climate Lobby, one of two groups that sued the state last year to prevent the use of offsets. The case was dismissed in January, the Bee reported.State officials say offsets give companies flexibility in how they meet the requirements of California’s 2006 climate-change law. That flexibility, they say, will help companies save money.“Offsets are a low-cost mechanism,” said Rajinder Sahota, manager of the California Air Resources Board climate change program evaluation branch.Offsets are part of the so-called “cap-and-trade” system adopted by California in 2011 to provide financial incentives for polluters to reduce greenhouse gas emissions.That system is a key part of the state’s landmark 2006 global warming law, AB 32, which seeks to reduce the emissions to 1990 levels by 2020.The “cap-and-trade” rules currently apply to more than 400 manufacturers, food processors and other big industrial firms, the Bee reported.