Michigan natural resources officials voted on Friday to lift a four-year moratorium on oil and gas drilling beneath Lakes Huron and Michigan. Supporters said the lake-bottom deposits would boost energy supplies in the U.S. while bringing the state royalty money that could be used to purchase public land. Critics said the risks of the drilling were too great, even though it would be prohibited in “environmentally sensitive” areas. Michigan Attorney General Jennifer Granholm (D), a candidate for governor next fall, hasn’t ruled out suing the state Department of Natural Resources to block the drilling. Other top state politicians, such as Lieutenant Gov. Dick Posthumus (R), who is also running for governor, and U.S. Sen. Debbie Stabenow (D), oppose the drilling. The DNR said it would take about a year to approve the first drilling permits.