SALT LAKE CITY — Gov. Gary Herbert on Tuesday announced the formation of a working group to develop the state's 10-year energy plan and outlined a broad strategy that doesn't call for limiting carbon emissions blamed for global warming.

The group's creation comes as the U.S. projects its greenhouse gases will grow by 4 percent through 2020, but Herbert isn't convinced that humans affect global temperatures. He had planned to hold what he called the first legitimate debate on the topic this spring, although none has occurred.

"The result of man's impact, great or small, on climate change and global warming is probably irrelevant. We want to have clean air and we want to have an abundance of energy that's cleaner and affordable," said Herbert, a Republican.

Last month, the National Academy of Sciences, which advises the government on scientific matters, called global warming an urgent threat and called for a carbon tax on fossil fuels or a cap-and-trade system for curbing greenhouse gas emissions.

Herbert has been a vocal critic of proposed cap-and-trade programs because he believes they would unfairly raise Utah's relatively low energy prices, which are heavily dependent on coal.

Some of Herbert's largest campaign contributors are energy companies, including Rocky Mountain Power. Its president, Rich Walje, will serve on Herbert's working group, along with officials from EMB Energy, Questar Gas and several state agencies.

The group's plan is due at the end of the year, although its unclear if the deadline will be before the November election.

A document provided by Herbert's office hints at what the group will pursue, although it provided few specifics.

Among other things, it says the group will work to promote energy efficiency, create energy-related manufacturing jobs and ensure continued access to clean and low-cost energy resources, such as coal.

Herbert tasked the group with accomplishing those goals and others without providing tax incentives.

"Solving the nation's energy crisis is more complicated than simply providing tax incentives to encourage people to install solar panels on their roof," the group's guiding document says.

No benchmarks for the use of renewable energy are set forth in the document, although Herbert said that could be addressed by the working group. Herbert said the use of renewable energy would grow because of the free market, although it was unclear how he intended to encourage the free market's growth. Herbert also said the group will examine the potential for nuclear power in Utah.

Herbert's environmental adviser and working group member, Ted Wilson, said public hearings would be held for environmental groups and others that want to provide input on the energy plan proposal.