Three of the four Democrats running for Arizona Corporation Commission said they believe Gov. Janet Napolitano cannot enter into a regional agreement to cap "greenhouse gases" on her own.

Kara Kelty, Paul Newman and Sandra Kennedy all said Wednesday they believe that the state needs to look at alternatives to electricity generated from fossil fuels, both from an environmental and an economic standpoint. The state remains heavily dependent on coal-fired "base load" plants as well as generators that use natural gas to meet peak demands.

But Newman and Kennedy said any move by the governor to set limits on emissions from those plants needs consent of the people whose job it is to regulate electricity rates - rates that could be affected if utilities have to either look for power from more expensive sources or buy pollution "credits" to continue to operate their coal-and gas-fired power plants.

Newman said he believes Napolitano should be required to obtain the "advice and consent" of the commission before inking any final deal, similar to the process for the governor to get consent of the state Senate for certain appointments.

Kennedy also sees a need for regulators to review and approve any deal Napolitano makes.

"She needs to work with the commission and not go off on her own," she said.

Kelty was a bit more flexible, saying Napolitano must get the approval of either the commission or, at the very least, the state Legislature. If nothing else, Kelty said, getting that approval is critical "mostly because there needs to be buy-in because there will be an effect."

Sam George, the fourth Democrat seeking one of three open seats on the panel, said he does not know whether the governor can proceed without commission approval. George said he would seek legal advice from Attorney General Terry Goddard.

Napolitano, a Democrat, signed an agreement with the governors of six other Western states and four Canadian provinces last year to cut greenhouse gases by 15 percent below 2005 levels by 2020.

One technique will be a cap-and-trade system starting with a 2012 inventory of how much greenhouse gas each source is emitting and a schedule of how much that needs to be cut and how fast. Companies unable to meet those reductions would be entitled to purchase pollution credits from other firms who cut emissions more than their target.

Gubernatorial press aide Jeanine L'Ecuyer said the question of whether Napolitano will seek permission from utility regulators is "not operative." She said staff members from affected states and provinces are still putting together the specifics of the cap-and-trade plan.

"They'll submit that to the governors and premiers," L'Ecuyer said. "And then we'll figure out what happens after that."

But Napolitano does have a record on the issue of her own power to regulate greenhouse gases: She vetoed a bill earlier this year which would have required legislative approval for any greenhouse gas rules, including cap and trade.

The argument that Napolitano needs corporation commission approval for any agreement is in line with views of several current commission members, all Republicans.

"I don't think there's any doubt about it," said Kris Mayes, a stance shared by Bill Mundell. Gary Pierce said while he's not sure the commission has to OK cap and trade, the governor needs at least legislative permission.

Bob Robson and Barry Wong, who served briefly as an appointed commissioner to fill a vacancy, also said Wednesday the governor needs commission approval.

But Rick Fowlkes, said the commission can't review or approve what the governor does because he believes she can't bind the state to greenhouse gas emission caps in the first place.

And Joseph Hobbs, running with Fowlkes and Keith Swapp as a team, was openly critical of the whole cap-and-trade concept.

Hobbs said it makes no sense to undermine the economy of Arizona, the region or the nation to reduce the human contribution to carbon dioxide levels, which he said amounts to a small fraction of 1 percent of the gas. He dismissed the premise that carbon dioxide emissions by humans can affect the climate as "this rabid global warming thing."

Kelty already is looking at how she would implement the system if she is elected. She specifically wants any cap-and-trade system to use a system of auctioning off the credits to the highest bidders rather than simply "grandfathering in" those already emitting greenhouse gases.