RICHMOND, Va. (AP) – Virginia Gov. Ralph Northam has vetoed legislation aimed at limiting his authority to institute a carbon cap-and-trade plan. Northam, a Democrat, said Thursday he had killed a bill that requires legislative approval before Virginia can participate in the Regional Greenhouse Gas Initiative, a cap-and-trade program among Northeastern and mid-Atlantic states that mandates emission reductions in the power sector. Northam has made implementing the plan a top priority, saying it’s needed to fight climate change. State regulators have said joining RGGI could add significant costs to electric bills. The governor also vetoed a similar bill related to limiting carbon emissions from cars. Both bills narrowly passed the GOP-led General Assembly. Republicans have virtually no chance of getting the needed two-thirds majority to override the veto.