Appalachian coal-mining interests have donated more than $60,000 to the US Senate campaign of Republican Carly Fiorina, the former HP chief executive who's said she's "not sure" that climate change is occurring. First reported by California Watch, the donations are the latest indication that California is a key battleground in the political war over climate change. While coal interests have virtually no business future in California (where existing laws are phasing out coal), they see the state's groundbreaking cap and trade law as key to their future. The successful implementation of the California law, which goes into effect later this year, could breathe new life into the US Senate's failed efforts to put a cap on carbon. As I've noted, Big Coal is bankrolling a ballot initiative that would suspend the California law, known as AB 32. Its donations to Fiorina go hand-in-hand with that effort: Unseating Democratic incumbent Barbara Boxer, the powerful chair of the Senate Environment and Public Works Committee, would drive another nail in cap and trade's coffin.