In the age of climate change, carbon dioxide emissions produced by burning fossil fuels present a liability that many investors fear might one day bring down oil companies. But scientists and policymakers are asking what would happen if carbon dioxide had a value the same way oil, gold and coffee do. What if it could be used to produce goods and even fuels — the way plants and trees use carbon dioxide to keep themselves alive?

It’s not an entirely new concept. For decades, industries from oil to soft drinks have bought small amounts of carbon dioxide, piped in from underground caverns where it was trapped eons ago. But now the outgoing Obama administration, along with partners from both environmental groups and the oil and gas industry, is hoping to create a much larger market that will not only keep carbon out of the atmosphere but create a new engine for the U.S. economy.

“They need scientific breakthroughs, but this is a very important research direction,” Energy Secretary Ernest Moniz said. “It could be building materials, road materials. A holy grail, in a certain sense, would be to use CO2 plus other ingredients like water and sunlight to convert to a hydrocarbon liquid fuel.”

Such breakthroughs are likely a long way off, but if they materialize, it could prove vital to the oil and gas industry. Solving the challenges and economics of carbon capture could keep oil, gas and other fossil fuels viable over the long term as international efforts to slow climate change lead to ever tighter restrictions on carbon dioxide emissions that accelerate global warming.

Burning fossil fuels in power plants, factories and other industries is a major source of the carbon dioxide that traps heat in the Earth’s atmosphere. For now, even the initial step toward putting carbon dioxide to use — separating it out of the emissions streams rising out of the country’s smokestacks — remains prohibitively expensive.

But as engineers work out the kinks, costs are coming down to the point that by 2025 it should be competitive with naturally occurring stockpiles, said Douglas Hollett, principal deputy assistant secretary for fossil energy at the Energy Department. He said carbon capture is on a similar trajectory as earlier energy technologies.

“Think about where solar PV, onshore wind [turbines], LED [light bulbs], and shale wells were not too long ago,” he said.

Colorless, odorless and noncombustible, carbon dioxide has a long list of theoretical applications. It can be used to make cement, feed algae, produce the bubbles in a can of soda, and even make fuels like methanol and ethanol. A report by the Energy Department’s scientific advisory board last month identified more than two dozen possible applications for carbon dioxide.

Turning those possibilities into reality is becoming increasingly important. As countries like Canada and Norway, and states like California increasingly move to put a price on carbon emissions, polluters are left with two options: Pay to have the carbon pumped underground or find someone to buy it.

By far the biggest use to date — and the one to which industry and policymakers are pinning their hopes for the foreseeable future — is within the oil and gas industry. Known as enhanced oil recovery, drillers for decades have pumped carbon dioxide into older oil fields to push the last barrels to the surface.

Since the Paris climate change pact, in which close to 200 world leaders last year agreed to control carbon emissions, most of the attention has focused on renewable sources like wind turbines and solar power. But in an Energy Department report this summer, scientists estimated that if the world were to meet the 2050 goal set in Paris, one-sixth of emissions reductions would need to come from carbon capture systems.

So far, political support has been hard to come by. Legislation introduced in Congress this past session would not only have increased incentives for carbon capture but fixed them permanently in the tax code. Despite bipartisan support — drawing together everyone from the environmentally minded Sen. Sheldon Whitehouse, D-R.I., to pro-oil Texas Rep. Joe Barton, R-Ennis — the legislation never even got assigned to a committee in the House or Senate.

But the new Petra Nova plant about to start running in Thompsons, Texas, about 30 miles southwest of Houston, is a bright spot for the technology’s supporters. It is being completed essentially on time and within its budget, unlike many previous such projects. When it fires up, the plant, which is attached to one of the power company NRG’s hulking coal-burning units, will draw 90 percent of the CO2 from the emissions produced by 240 megawatts of generated power. That is a fraction of the roughly 3,700 megawatts produced at this gargantuan plant, the largest in the Lone Star State. Still, it is enough to capture 1.6 million tons of carbon dioxide each year — equivalent to the greenhouse gas produced by driving 3.5 million miles, or the CO2 from generating electricity for 214,338 homes.

Petra Nova, a billion-dollar joint venture of NRG and JX Nippon Oil and Gas Exploration, will push compressed CO2 through a new pipeline 81 miles to an oil field, where will be injected into wells. That should increase production to 15,000 barrels per day from about 300 barrels per day. And since NRG owns one quarter of the oil recovery project, what comes out of the ground will help pay for the carbon capture operation.

The New York Times contributed to this report.