ClimateWire: Bill White wants his home state to use a lot less coal. The man vying to be Texas’ first Democratic governor in more than a decade mentions the fossil fuel immediately when asked about the biggest difference between himself and Republican Gov. Rick Perry. Nationally, White said he would like to see coal’s usage drop from 50 to 35 percent, a decline he said could occur in a dozen years or sooner. By taking a Houston energy-efficiency program statewide, pushing for solar …