BURNHAM, N.M. — For the Navajo nation, energy is the most valuable currency. The tribal lands are rich with uranium, natural gas, wind, sun and, most of all, coal.
But two coal-fired power plants here, including one on the reservation, belch noxious fumes, making the air among the worst in the state. Now the tribe is moving forward with plans for a bigger plant, Desert Rock, that Navajo authorities hope will bring in $50 million a year in taxes, royalties and other income by selling power to Phoenix and Las Vegas.
The plan has stirred opposition from some Navajos who regard the $3 billion proposal as a lethal "energy monster" that desecrates Father Sky and Mother Earth and from environmental groups that fear global warming implications from its carbon dioxide emissions.
New Mexico, which has no authority over the tribal lands, has also expressed misgivings and has refused to grant the plant tax breaks.
The struggle is a homegrown version of the global debate on slowing climate change.
Developed countries are trying to reduce emissions of carbon dioxide, the most ubiquitous gas usually linked to climate change, and argue that rapidly growing nations like India and China should avoid building coal-fired power plants. The critics' targets say it is unfair to keep them from powering their way to prosperity with cheap and abundant coal.
The Navajo president, Joe Shirley Jr., said his tribe felt similar pressure. Mr. Shirley said the plant here would mean hundreds of jobs, higher incomes and better lives for some of the 200,000 people on the reservation. The tribe derives little direct financial benefit from the operation of the existing coal-fired plants and it has not yet invested heavily in casinos.
"Why pick on the little Navajo nation, when it's trying to help itself?" he asked.
The Sierra Club and the Natural Resources Defense Council, teaming with local groups like the San Juan Citizens' Alliance, point to environmental shortcomings in the federal government's tentative blessing of the plant, as laid out in a 1,600-page draft environmental impact statement and an analysis by the Bureau of Indian Affairs.
The staff of Gov. Bill Richardson, a Democratic presidential aspirant, recently issued a statement saying that the plant "would be a significant new source of greenhouse gases and other pollution in the region" and that Mr. Richardson "believes, as planned, it would be a step in the wrong direction," undoing his proposed reductions in emissions.
In 2003, the Navajo invited Sithe Global Power, a merchant power company based in New York, to build the $3 billion 1,500-megawatt plant with the Navajo-owned Dine (pronounced dee-NAY) Power Authority.
In most respects, the plant would be relatively clean, with emissions of mercury, soot and smog-forming pollutants lower than most such operations. But each year, it would emit 12 million tons of carbon dioxide, the equivalent of adding 1.5 million average cars to the roads.
Coal-fired electricity contributes more than half of the 57 million tons of annual carbon-dioxide emissions in New Mexico. Together, the two existing plants emit 29 million tons.
Tom Johns, a vice president of Sithe Global Power, said he, too, was concerned about climate change. Desert Rock, Mr. Johns said, would be part of the solution.
"Carbon is emitted when we use energy," Mr. Johns said. "By not building one plant but another or by using older inefficient plants instead of new ones, we don't solve the problem. The solution to carbon issues is to be more efficient in how we use energy."
Worries about pollution from a new plant build on lingering concerns about the ill effects of previous energy exploitation on the tribal lands. Navajos have been sickened and killed by uranium tailings, leading the tribal government to ban uranium mining. Mercury contamination has led New Mexico to warn children and pregnant women against eating large carp and catfish from much of the San Juan River, which passes through the northeastern end of the 26,600-square-mile reservation. And the ozone levels in San Juan County, which includes the eastern part of the reservation, have exceeded suggested new federal standards.
Elouise Brown, a Navajo whose family is from the area around the proposed plant, has led a group called Dooda (pronounced dough-DAH) Desert Rock, Navajo for "No to Desert Rock," in a seven-month protest at the site.
The tribal council voted overwhelmingly to back the project, but Navajos are divided, with each side claiming to speak for the majority.
"It's not just that it's so close to my house or my family," Ms. Brown said. "It's the pollution and what the impacts are going to be from the pollution to all the people that live there. Not only the people that live there, but it adds to global warming. So it's going to be a worldwide issue."
The fight, in one of the emptiest regions, echoes in many respects the debates over the more than 100 proposals to build coal-fired power plants.
Organizations like Environmental Defense and the Natural Resources Defense Council have the equivalent of strike forces criticizing proposed plants. They recently won a victory in Florida, where regulators rejected two plants.
A major Texas utility, TXU, was bought by a financial group that agreed to scrap 8 of its 11 proposed coal-fired plants.
The Desert Rock fight is complicated by the status of the Navajos as a sovereign nation within a nation. Although some federal approvals are required for the project to proceed, no state regulators can tell the tribe what to do. Even with their divisions, the Navajos are thinking big about the possibilities. The tribal council is trying to find banks to lend it up to $750 million to buy a 25 percent ownership stake.
The council also plans a transmission line to carry electricity from Desert Rock and, perhaps, future wind farms.
The arrangement would be lucrative for the struggling tribe, which earns $102 million a year, much of it from selling coal and other minerals, and $400 million or so in government grants. The new power line might help send electricity to 20,000 remote houses — one-third of the residences on the reservation — that lack it.
Local opponents, like Mike Eisenfeld of the San Juan group, are more concerned about potential health and environmental costs.
"Your conclusion when you read the federal environmental impact statement is things are so bad already that you won't even notice another power plant," Mr. Eisenfeld said.
Some backers of the plant hope that Desert Rock could be a proving ground for an experimental technology to reduce carbon emissions by capturing them and injecting them deep in the ground.
Mr. Johns of Sithe Global Power and Senator Jeff Bingaman, the New Mexico Democrat who is chairman of the Senate Energy Committee, expressed hope that the carbon-capture technology could be incorporated into the plant with an additional $1 billion investment.
The Senate Finance Committee approved a measure for a production tax credit of $20 a ton for sequestered carbon dioxide, and Mr. Bingaman said he was looking for bill to attach it as an amendment.
Mr. Shirley, the Navajo president, said he hoped that the plant would be running by 2012. That may be optimistic. The plans are subject to final approval not only by the Bureau of Indian Affairs, but also from at least three other federal agencies. If they come, lawsuits are a good possibility.