Iowa Attorney General Tom Miller is among 18 state attorneys general who are joining the Environmental Protection Agency's legal fight to uphold the Clean Power Plan by submitting briefs in support to the D.C. Circuit Court this week.

In a teleconference Wednesday, Miller said Iowa has "an enormous amount at stake" in enacting the Clean Power Plan to reduce carbon emissions.

"We are so dependent on agriculture and farmers, and climate change presents enormous problems for farmers," he said. "We have pretty close to ideal temperatures for farmers right now; that could change. Another important issue is flooding. It had been something that we could deal with readily before in Iowa. Not anymore."

Federal regulators on Tuesday filed their first defense of the Clean Power Plan in a court case addressing the law's merits, arguing to the U.S. Court of Appeals for the District of Columbia that it has the authority to limit emissions from existing power plants, Utility Dive reported.

Carbon dioxide and other greenhouse gases pose a "monumental threat to Americans' health and welfare," the EPA said, and the new limitations would "secure critically important reductions."

The Clean Power Plan is targeting a 32 percent reduction in carbon emissions from the power sector nationwide by 2030, but the U.S. Supreme Court has delayed the rule's implementation while the D.C. Circuit Court considers challenges.

Opponents of the rule say the EPA is overstepping its authority under the Clean Air Act, and that the rule will hurt state economies still heavily tied to coal-fired generation.

For Iowa, the plan is "really quite doable," Miller said, noting that the state's two major utility companies "are on board with this and can see their way to compliance."  

The CEO of one of the nation's largest utility companies called the Clean Power Plan "exactly the right approach for reducing carbon emissions on a broad scale," and said he believes the CO2 reduction targets in the plan are achievable.  

"For years, our industry has said there is no one size fits all, and the Clean Power Plan recognizes that," said Anthony Earley Jr., chairman, president and CEO of California-based Pacific Gas & Electric Co. "Each area of the country can decide what makes sense for them (for alternative energy sources)."

About 55 percent of the electricity that PG&E supplies to customers currently comes from renewable or carbon-free sources, Earley said.

"We recognize that if we don't do something, we're going to start to see (climate) consequences," he said.