Pennsylvania's publicly owned forest lands could be used for the underground storage of carbon dioxide captured from coal-burning power plants and other industrial sources of the greenhouse gas that is a major cause of global climate change.

The process -- which is not yet commercially feasible -- involves capturing carbon emissions from a facility's smokestack, compressing the gases into a liquid and then pumping it at least a half mile underground.

According to a state Department of Conservation and Natural Resources study report scheduled for release next week, it would be appropriate and important to Pennsylvania's environmental and economic future to use public lands as part of a still undefined state strategy to rein in climate change.

"Coal is with us and will be part of the energy mix for the foreseeable future, but if we want to avoid frying the planet, we're going to have to do something about controlling carbon emissions," said John Quigley, DCNR chief of staff. "What is the fastest way for that to happen? Well, we've advanced the idea that public lands should be looked at, should be part of the mix."

There are more than 2.1 million acres of publicly owned land in Pennsylvania, and the state is by far the biggest landowner. It also owns the mineral rights under 85 percent of that property, thereby simplifying the legally complex surface rights-mineral rights ownership questions surrounding most private property.

Mr. Quigley said using public land to sequester carbon collected from utilities and industries and public financing to support a pilot carbon sequestration project could put the state in position to benefit economically from efforts to reduce carbon emissions by 80 percent by 2050 -- the minimum amount needed to reduce the impacts of climate change.

The report will recommend that a statewide geological assessment be undertaken to identify underground geological formations where potential carbon sinks could be located.

The document also says that any pilot project built to test the still emerging technology of carbon capture and sequestration should be sited in the western part of the state, where major industrial and utility sources operate and where much more is already known about the underlying geology because of extensive oil and gas drilling records going back 100 years.

The geological records from well drilling are important because the carbon, once compressed into a liquid, would be pumped deep underground into depleted oil and gas reservoirs, deep coal seams, or shale or saline formations. The technology may be 15 years from commercial application.

Mr. Quigley said no specific site for either construction of a demonstration carbon capture facility or the sequestration of the carbon that would be collected has been identified. Any decision to allow sequestration of carbon on public lands is probably years away, and, he said, would require legislative approval.

"This is the first step in a long journey for Pennsylvania and the country to make changes in how we use energy," Mr. Quigley said. "We're trying to be ahead of the curve here."

But the Sierra Club and other environmental groups say that while they want to see the Pennsylvania's oversized carbon footprint significantly reduced, thy don't think it's fair for public lands to be used as a dumping ground for a fossil fuel-based utility industry that isn't investing enough in cleaning up its emissions.

Joseph Minott, executive director of the Clean Air Council, a Philadelphia-based environmental group, said using public land opens the state up to liability if the unproven technology contaminates groundwater or leaks out into the atmosphere, and questions why the state should "provide another subsidy" to the coal and utility industries.

"I'm a little leery about making public land available when our carbon emissions have increased by 11 percent over the last five years. I'd like to see more of a focus on reducing emissions from existing sources," said Jeff Schmidt, the Harrisburg lobbyist for the Sierra Club. "We know coal will be part of the energy mix, but right now it is supplying 58 percent of our electricity and we're addicted. We need to be pursuing alternative energy sources to wean ourselves off of it."

Man-made carbon dioxide emissions worldwide have increased from an insignificant level two centuries ago to more than 33 billion tons a year, with 8.8 billion tons of that from the United States. The higher emissions have increased the amount of atmospheric greenhouse gases, which trap radiant heat from the sun and cause global warming and potentially unhealthy changes in regional climates.

Pennsylvania emits more greenhouse gases than 105 developing nations combined and, according to the National Environmental Trust, emits 1 percent of the entire planet's global warming pollution.

According to the DCNR, Pennsylvania has the potential to store 100 years worth of carbon at present emission rates in its geological formations, mine lands, wetlands, forests and farmlands.

After the report is posted on the DCNR Web site next week, the department will open a 30-day public comment period.

"We hope this is the start of a long conservation whose outcome will impact how we generate energy over the next 100 years," Mr. Quigley said. "Any demonstration project will require significant private sector interest, but we don't have that now. We think it's appropriate to seriously consider use of public lands because it might not happen any other way."