Under the California Environmental Quality Act (CEQA), where a project will have significant environmental impacts, the agency undertaking or permitting that project must impose all feasible mitigation. For some types of impacts, mitigation is straightforward (for example, requiring replacement wetlands for wetlands that will be developed). For other types of impacts, such as climate change, the science is evolving and will continue to inform us what mitigation is available, and what works best.
There are many helpful resources that set forth potential mitigation for greenhouse gas emissions (the type of pollution that causes climate change). These include Attachment 3 to the 2008 Technical Advisory, pdf. issued by the Governor’s Office of Planning and Research (OPR) and the 2008 white paper, CEQA and Climate Change, issued by the California Association of Pollution Control Officers (CAPCOA). OPR’s CEQA and Climate Change webpage contains links to additional guidance, including detailed explanations of the 2010 changes to the CEQA Guidelines that specifically cover analysis of climate change impacts.