The head of Arizona’s environmental agency is asking state lawmakers to remove rules they imposed on the Department of Environmental Quality in 2010. The restriction bars ADEQ from regulating greenhouse gases. 

Henry Darwin says a new rule from the Environmental Protection Agency requires the state to cut emissions 52 percent from 2005 levels in the next 16 years. 

Darwin told members of a state House Committee his agency is weighing a legal challenge against the EPA.

“But fact of the matter is — and I'll be honest — that states and industry have not been very successful as of late in challenging EPA's ability to regulate greenhouse gases. So I don't hold a lot of hope to a challenge to EPA's proposed rule," Darwin said.

The 2010 law was enacted to overturn rules pushed through by then-Gov. Janet Napolitano, to require new vehicles sold in the state to be more fuel efficient.

With Napolitano long-gone, Darwin says the restrictions on his agency are no longer needed.