More than 50 strategies to cut greenhouse gases -- from making government buildings more efficient to reducing tailpipe emissions -- were recommended Tuesday by a panel established to help state lawmakers develop a global warming plan.

If all 56 recommendations of the N.C. Climate Action Plan Advisory Group were adopted, the state would return to 1990 levels of greenhouse gas emissions within 13 years -- despite three decades of rapid growth. That would cut projected emissions to nearly half what they would be if the state did nothing, according to the group's draft report.

The 43-member group met Tuesday to refine the report, which they expect to submit to state lawmakers by the end of the year. A separate, overlapping group is advising lawmakers on which proposals to adopt as laws.

The proposed changes include remedies large and small, such as trapping methane-producing animal waste and upgrading coal plants with new technologies.

Most are aimed at using less energy to cut the amount of carbon dioxide and other greenhouse gases.

"The important underlying theme in the recommendations is energy conservation and efficiency," said Tom Mather, a spokesman for the Division of Air Quality, which has overseen the group's efforts. "That's where you're going to yield the most reduction."

Mather said another group of reforms aims to remove carbon dioxide from the atmosphere by preserving forest land and trees.

The reforms would have an affect on businesses, government offices, farms and the marketplace -- in ways critics say won't be popular.

Proposals such as a adopting a statewide cap for greenhouse gas emissions would raise energy costs for everyone, said Roy Cordato, vice president for research at the John Locke Foundation, while a focus on controlling growth would restrict land use.

He said his group will fight proposals as they move through the legislature, and he expects others to do the same.

"I would expect a groundswell of opposition once it becomes clear that they're asking citizens to pay higher taxes and have their freedoms restricted," Cordato said.

The climate group's preliminary cost estimates show that adopting the measures could create tens of thousands of jobs and expand the state's economy by opening entrepreneurial opportunities. The measures would also create savings in energy costs, though some of those gains would be offset by the upfront investments in new technologies.

The advisory group was created in 2005 to come up with ways to curb the effects of global warming. Composed of representatives from businesses, government agencies, universities and environmental groups, its recommendations will be considered by the Legislative Commission on Global Climate Change. That commission will determine whether to advocate their adoption by the General Assembly.

But some of the advisory group's proposals don't require legislative approval. Mather said the state Division of Air Quality will start measuring the carbon dioxide emissions from various industries, for instance, which they had never done before.

Others have already been adopted, such as a new law requiring the increased use of renewable energy sources.

The group culled the 56 proposals out of a list of more than 300 ideas in a process that was sometimes contentious, said Jim Southerland, an environmental engineer who oversaw a working group on energy use.

"We didn't have anybody shouting or coming to blows, but people were divided," he said.

Now that the proposals are set, the larger battles are likely to come as the legislature picks and chooses among them.

"I think we would be fooling ourselves if we said we expected all this to be done," Southerland said.