It's trash when it's spewed into the atmosphere from burning fossil fuels. But it's treasure when it's pumped into an oil reservoir.

The world's top scientists believe man-caused carbon dioxide emissions are a key contributor to global warming. But whether the greenhouse gas is a pollutant or a commodity largely depends are where it is in the world.

"In some places, they're going to have to give (CO2) away. In Wyoming, I don't know," Steve Melzer said. "It's more a function of geography than supply."

Melzer, a private consultant, was a keynote speaker at the Wyoming CO2 Conference at the Parkway Plaza in Casper on Thursday. The event, sponsored by the University of Wyoming's Enhanced Oil Recovery Institute, continues today and is free to the public.

In Wyoming, CO2 is a highly sought-after commodity. There's more demand for CO2 to squeeze additional flows from aging oil fields than there is CO2 supply. That's because the current "commercial" supply of CO2, or CO2 that is isolated, pressurized and pipelined, comes from natural gas processing plants.

That amounts to about 225 million cubic feet of CO2 per day, and will soon increase to 270 million cubic feet per day. State regulatory officials say there's a mad scramble among prospective "enhanced oil recovery" producers to contract for the entire supply.

With half of all wells under the "marginal" production category, many Wyoming producers will miss out on the high-riding price of oil.

Melzer said both the U.S. coal and oil industries are at the cusp of a major transition with regard to CO2. Although enhanced oil recovery through CO2 injection has steadily increased over the past few decades, future CO2 flooding projects could depend on whether they can recover more CO2 from deep natural gas production.

In other words, the oil industry needs short-term access to CO2 that can quickly make a return on investment. Few in the industry are making CO2 flooding plans in anticipation that new CO2 supplies will come from coal-fired power plants.

Melzer said he works closely with policy-makers, and he's concerned that carbon control regulations could "mess this up."

"The government has its focus on long-term sequestration assuming it's all waste injection," said Melzer, referring to pumping CO2 into deep underground aquifers and other underground formations without the additional use of enhanced oil recovery.

Generally, there's not a lot of information available about deep saline aquifers for carbon sequestration. Oil producers, of course, are most familiar with the oil-bearing formations they've targeted for years, and that's where the oil industry is prepared to make its CO2 investments, Melzer said.

"Industry looks at shorter-term deployment of new technologies, and focus on a quicker return on investment. So there's clearly a disjoint here," he said.

Some industry experts estimate there's about 100 million cubic feet of CO2 emissions per day for every 100 megawatts of coal-fired power. That would mean Wyoming's 6,000-plus megawatts of coal-fired electrical generation emits 6 billion cubic feet of CO2 into the atmosphere over Wyoming's aging oil fields every day. So far, industry doesn't consider that resource to be economically viable to capture from the flue stream, compress and put into a new network of pipelines.

For now, the oil industry's main supply of CO2 will be from its counterparts in the deep natural gas business. And Melzer said that industry has not yet realized the potential for CO2 as a commodity.

"It's a little bit embarrassing that the natural gas processing industry hasn't seen this (sooner)," Melzer said.

Energy reporter Dustin Bleizeffer can be reached at (307) 577-6069 or dustin.bleizeffer@trib.com.