DAYTON -- Texas doesn't get much credit when it comes to the fight against global warming.

Texas easily leads the nation and is the world's seventh-largest polluter of carbon dioxide emissions. And some of the top political leaders, including Gov. Rick Perry, still question whether man is contributing to climate change.

But deep in the piney woods around this East Texas community, accessible only by unmarked dirt roads, crews are working on one of the great hopes in the battle to reverse the trend.

This is Texas oil country. All around, tucked in the dense and swampy woods, rusty pumps operate as they have for decades. At first glance, it seems an unlikely place for a cutting-edge solution to the most politically charged environmental problem of our time.

Susan Hovorka, a senior scientist with the University of Texas Bureau of Economic Geology, has chosen this spot to do a little pumping of her own. However, she's pumping carbon dioxide underground instead of pumping oil and gas out.

The technology -- carbon sequestration -- siphons carbon dioxide from power plants or other industrial facilities into the ground instead of letting the greenhouse gas escape to the atmosphere. And here, on an old oil pad in the Texas woods, is one of the most advanced and successful test projects.

"Texas and the Gulf Coast are usually slammed, but it is showing promise for a big environmental cure," Hovorka said.

This is part of the dichotomy in the Lone Star State when it comes to battling greenhouse gasses.

Many see Texas as a haven for oilmen and industry that long have lobbied to keep global warming regulation out of the policy debate.

But Texas has also been a pioneer in renewable energy, a trend started when George W. Bush was governor.

The state now boasts one of the most progressive renewable energy programs in the country. That program is dominated by wind power -- Texas passed California last year to become the top generator of wind power in the nation -- but it also includes some provision for solar and biomass power.

Also, two Texas sites, Jewett and Odessa, are finalists for the Energy Department's FutureGen project, a $1.5 billion coal plant that employs cutting-edge technology with the goal of producing energy while emitting nearly no pollutants. And nationally, experts view Texas and the Gulf Coast as one of the areas with great potential to battle global warming with carbon sequestration.

1 law out of 12 bills

In some ways, this was a historic year for global warming measures at the state capital.

"It's a huge step forward," said Tom "Smitty" Smith, director of Public Citizen's Texas office. "What you now have are members of the Legislature openly acknowledging that global warming is of concern to them."

A dozen bills were filed this year to specifically address global warming. That compares, according to a Houston Chronicle analysis, to only one in the 10 legislative sessions before.

The numbers are telling, Smith said. But the "huge step," he admits, signals more of an emerging shift in thought than in political action.

Of the 12 bills filed, only one became law, and that was significantly diluted. The bill requires water planners in West Texas to consider the effects of climate change when developing water-supply strategies. When Sen. Eliot Shapleigh introduced the bill, he envisioned it affecting statewide water decisions. But the El Paso Democrat had to limit the impact to West Texas to pass the legislation.

Rep. Lon Burnam filed four bills, the most by any legislator, to deal with the issue. None passed. The Fort Worth Democrat did manage to get a piece of one bill -- one that created a committee on energy generation and its environmental impact -- attached to a bill that passed.

But the governor ultimately vetoed the committee, saying it would only duplicate the efforts of the Texas Commission on Environmental Quality.

"It really was sad," said Jim Marston, Environmental Defense's regional director in Texas, who summed up the session in less glowing terms than Smith.

"Baby steps," he said. "We made progress, but we are still behind the mainstream and (behind) many states."

Some 33 states, led by California, are trying to institute statewide or regional limits on carbon dioxide.

It looks unlikely that the powerful oil industry ever would back such a move in Texas.

San Antonio-based Valero Energy Corp., the largest refiner in North America, supports voluntary emissions reduction and "market-based mechanisms and incentives" to reduce emissions, but is ardently against regional or state plans to do so.

"It would be better to have a national standard," spokesman Bill Day said. "That would be more fairly implemented."

Jeff Holmstead, who headed the Environmental Protection Agency's air office from 2001 to 2005 before moving to the law firm of Bracewell & Giuliani, echoed the stance.

The former Bush administration official now works for a firm known as one of the most influential in the energy industry. It represents and advises some of the biggest utilities in the country, including Energy Future Holdings, formerly known as Dallas-based TXU Corp., and also lists top oil players in its client list. These include the National Petrochemical & Refiners Association and Valero.

Holmstead vehemently argues it would be foolish and harmful to local industry if states were to place caps or fees on carbon dioxide gases before the federal government does so.

He said it's best for the state governments to leave industry alone to prepare for whatever national or international rules eventually emerge to regulate carbon dioxide.

"The fact that there is no state law requiring them to do so doesn't mean they're not doing it," he said. "Every major manufacturing company that I know of is spending a lot of time thinking about this."

Battleground state

The state's lack of action on global warming policy doesn't mean it hasn't been a significant battleground on the issue.

Texas carbon dioxide emissions of 670 million metric tons in 2003, the latest year available, were nearly double the amount released in California, according to the Energy Information Administration. The biggest emitters in Texas are industrial facilities, followed closely by electric generation plants, then cars and trucks.

The volume could have gone up significantly in the next few years if the state's largest utility had its way. TXU was the leader of what many characterized as a "coal rush" in Texas. The utility wanted to build 11 coal-fired power plants that would have spewed another 78 million tons of carbon dioxide into the atmosphere.

The company had the outspoken support of Perry, who ordered state agencies to fast track all permits for new power plants. But the effort stalled when an unlikely coalition of environmental groups, Texas mayors, property owners and business leaders fought the plants.

Eventually, the company dropped plans for eight of the 11 plants when a buyout emerged that was brokered in part by the advocacy group Environmental Defense. The buyout included a provision that the company would reduce its overall carbon dioxide emissions to 1990 levels by 2020.

Judi Greenwald with the Pew Center on Global Climate Change said the deal grabbed attention across the country.

"TXU had been a poster child for building coal plants willy-nilly before they turned around," she said. "I think that had a big impact on the debate. I think that sort of turnaround in Texas was politically significant."

Greenwald also said Texas' penchant for renewable energy, particularly wind, has helped the industry as a whole shed any stigma that might be associated with green issues in some segments of the country.

"It makes it seem more macho, more mainstream and less crunchy," she said.

Carbon storage

The way UT scientist Hovorka explains it, there's a nice symmetry to the idea of carbon sequestration. Carbon released into the air generally is pumped out of the ground first as oil or gas. So why not push it back into the Earth?

The potential storage capacity is enormous.

According to the National Energy Technology Laboratory, the deep saline formations in the U.S. and parts of Canada could hold somewhere between 1 trillion and 3.7 trillion tons of carbon dioxide. For perspective, that's 241 to 866 years' worth of U.S. emissions from industrial and power plants, measured at current levels. And those estimates are conservative because they're based on just 1 percent to 4 percent of the saline formations' potential storage capacity.

Other geological formations have potential for carbon storage, such as oil and gas reservoirs and unmineable coal seams. But deep saline formations, which are underground areas that contain salty water, are thought to hold the most promise. And there's a swath of them along the Gulf Coast from South Texas through Alabama.

This is the type of formation Hovorka is using in the woods of East Texas.

She's pumped carbon dioxide about a mile under the ground surface into the porous sandstone of the Earth's crust, where it displaces brackish water already trapped there.

Where that water goes is of concern to Hovorka and her fellow scientists. The worst-case scenario is that it seeps into an aquifer and fouls potable water supplies. But given the amount of room in the saline formations and the very slow rate of movement, Hovorka doesn't believe the issue is a "show stopper."

Of course, carbon sequestration is valid only if the carbon dioxide stays in the ground.

That's what Hovorka's checking on today. Crews have pumped about 2,000 tons of carbon into the ground. Now they want to know if it has escaped through any of the many oil wells in the area that represent direct conduits into the saline formation.

Because carbon dioxide is ever present in the environment, it's nearly impossible to scan specifically for the greenhouse gas coming from the test site. So crews have injected a tracer chemical, perfluorocarbon, with the carbon dioxide.

The field test doesn't look terribly high-tech. A technician trudges through gravel and knee-high foliage near one of the old pump jacks close to the test site. He's wearing an odd-looking vest and pulling a metal canister that clanks and bumps over the uneven ground.

When done, he pulls small tubes of air that he's sucked up through the canister into the vest and drops them off at a mobile lab parked a hundred yards or so from the pump jack.

None of the technology here is new. It's all what Horvorka calls "off-the-shelf equipment" commonly used in Texas oil operations and industry. But the combination is cutting-edge. This is the first site to use seeper trace technology in a carbon storage test.

Amazingly, the equipment has the ability to detect the chemical in parts per quadrillion. That's a 1 followed by 15 zeros.

"It is the most advanced one (field test) that we have right now," acknowledged Bob Kane, technical adviser for carbon management at the National Energy Technology Laboratory.

Crews haven't found leaks from the ground.

"No detect. No detect. No detect," Hovorka said as results become available from the mobile laboratory. "That's good news."

The next step, Kane said, is to increase the size of testing to 1 million tons or more to prove the technology is effective on a larger scale. The goal is to make the technology commercial available by 2012 without raising the price of electricity by more than 10 percent.

For carbon sequestration to work, plants that produce carbon dioxide first must separate and capture the gas. If there isn't a nearby formation capable of holding the gas, it would have to be transported via pipeline or some other method.

Old coal-fired power plants can be retrofitted to capture the gas, but the cost is so high the method is thought to be economically unfeasible, Kane said.

The most promising method is to marry carbon sequestration to a new generation of coal plants that would use a new gasification method known as integrated gasification combined technology. This method of extracting energy from coal makes it much easier to capture carbon dioxide and other pollutants.

Even with TXU scaling back its expansion plans, 13 coal plants are still under construction or proposed for the state. And only one, proposed by Houston-based Hunton Energy, plans on using IGCC technology. The company hopes to have the first phase of the plant running by 2011. Plans also call for sequestering a small part, 10 percent to 15 percent, of the plant's carbon dioxide.

The other 11, including the plant being built in San Antonio by CPS Energy at Calaveras Lake, make no provisions for their greenhouse gases. San Antonio's plant should be running by the summer of 2010 and will release an estimated 7 million tons or more of carbon dioxide into the air every year.

Environmental groups that fought the plant pushed hard for IGCC as an alternative. But utility officials adamantly refused, arguing the utility could not risk millions on unproven technology.

Only two such plants exist in the country, in Florida and Indiana. Both were heavily funded by the U.S. Energy Department, and neither traps carbon dioxide by pumping it into the ground.

Luminant, a subsidiary of Energy Future Holdings, has promised to build two plants using IGCC or some other gasification technology capable of sequestering carbon, but hasn't set a timeline.

Given the uncertainty of the technology and CPS Energy's conservative nature, it's unlikely the public utility will build an IGCC plant anytime soon, said Robert Temple, the utility's deputy general counsel.

"CPS Energy has never been serial number 1 on anything," he said.