When Exxon Mobil Corp. endorsed a carbon tax proposal initiated by former Secretaries of State James Baker and George Shultz, some observers foresaw a future with dramatically fewer regulations. Not W. Thaddeus “Thad” Miller, the executive vice president and chief legal officer of Houston-based electricity provider Calpine Corp., who also endorses the Baker proposal.

If the carbon tax becomes reality, “this is not as large a change on the regulatory front as people may think,” Miller says.

Thad Miller.