A broad coalition of advocates has been meeting quietly to discuss a path forward on climate and fiscal policy, including proposals for a carbon tax.

The ad-hoc, left-right group has held several closed-door meetings since 2011, most recently gathering on Wednesday afternoon at the conservative American Enterprise Institute (AEI) in Washington, D.C.

The meetings follow the 2010 collapse of cap-and-trade legislation on Capitol Hill, and occur at a time when many Republicans are hostile to any proposals to limit greenhouse gas emissions.

David Jenkins of ConservAmerica, which was formerly called Republicans for Environmental Protection, has been attending the meetings and described them as “casual, brainstorming conversations.”