By Timothy Cama, The Hill.

Former New York City Mayor Michael Bloomberg is paying to run negative advertisements targeting four state attorneys general for their legal actions against a key climate change rule.

Bloomberg’s advisers told The New York Times that the campaigns would cost more than $10 million, to defend President Obama’s regulation to slash carbon dioxide emissions from power plants.

The ads, through Bloomberg’s Independence USA PAC, target Pam Bondi of Florida, Bill Schuette of Michigan, Brad Schimel of Wisconsin and Chris Koster of Missouri. Koster is running for governor.