Nearly half of oil and gas emissions could be cut without spending a penny

As the world's economy rebounds from the COVID-19 pandemic, demand for oil and gas is set to increase — and so is the emission of methane, a potent greenhouse gas with 80 times the heat-trapping power of carbon dioxide. The fossil fuel industry is one of the biggest sources of human-generated methane emissions, emitting 70 metric tons of the polluting gas last year — roughly equivalent to all the carbon dioxide produced by the European Union. 

Now for the good news: About 40% of methane emissions from oil and gas production can be eliminated without costing a cent, the U.S. Energy Information Agency said in a recent report. Cutting down that number "is among the most cost-effective and impactful actions that governments can take to achieve global climate goals," according to the agency.

Plug the leaks

Natural gas is produced by drilling or hydraulic fracturing (better known as fracking), and is also extracted as a byproduct of drilling for oil. Because the gas is invisible and odorless, detecting leaks can be challenging. And leaks can occur at any point in the process, from extraction out of the ground to the moment where the gas is burned in a power plant.

Among the most cost-effective steps natural gas producers can take is replacing old equipment, the EIA notes. Many pumps, valves and compressors on a gas-drilling pad emit methane in the course of their operations, and tend to emit more as they age — especially if they aren't maintained. The EIA recommends replacing many components early and replacing gas-powered parts with electrified versions, which leak less gas in their operations.  

Detecting leaks early and often, through technology such as infrared cameras or satellite imaging, can also help plug up leaks. The EIA also recommends eliminating the practice of venting, or releasing natural gas straight into the atmosphere, in order to empty a pipe for maintenance or when extraction companies are getting rid of unwanted natural gas to collect oil.

"Natural gas is essentially just methane, and in many cases if you can avoid that methane leak, you can sell that gas for profit," Christophe McGlade, the head of IEA's Energy Supply Unit, told CBS MoneyWatch.

"Big part of global warming"

These recovery steps all result in gas producers having more product to sell, so they tend to be more valuable for the industry when the cost of gas is high. In the U.S., gas prices have been low for years, thanks to the fracking boom, and is one reason why U.S. oil and gas producers have been loath to crack down on methane leaks. 

"You have, I wouldn't say an oversupply of gas, but you're very flush with gas. So the financial numbers for reducing [leaks] with no external pressure are actually quite low," said Dan Zimmerle, a senior research associate at the Energy Institute of Colorado State University.

Recent research has shown that oil and gas extraction emits much more methane gas than previously believed. Satellite imaging last year revealed that the Permian Basin in West Texas was leaking enough methane every year to power 7 million households. Some 3.7% of the gas extracted from the area was lost as emissions, a study from the Environmental Defense Fund found.

That figure matters because the leakage rate of methane is directly tied to its role as an ostensibly low-emissions fuel. If just 1% of captured gas escapes, "there's no doubt that it's better than coal; there's no doubt that it's better than just about any fossil fuel source there is," said Zimmerle. 

At a leakage rate of 2% or 2.5%, however, burning natural gas has the same climate impact as burning coal. Research by other scientists, including Robert Howarth, a professor of ecology and environmental biology at Cornell University, shows that the oil and gas industry's leakage rate may be even higher — approaching 4%. 

Concentrations of methane in the Earth's atmosphere have increased steadily since about 2010, after staying flat for the first decade of this century.

"My research suggests that most of that is coming from the oil and gas industry, and it's responsible for a big part of global warming," Howarth said. 

Congress recently moved to crack down on greenhouse gas emissions from extraction sites, opening the door for the Environmental Protection Agency to craft tighter rules for the industry.

To date, human-caused greenhouse gas emissions have warmed the planet by about 1.1 degrees Celsius, research shows. About a quarter of that warming is attributed to methane, Howarth said.

Methane stays in the atmosphere for a shorter period of time than carbon dioxide, dissipating after several decades, while CO2 stays in the atmosphere for centuries. But methane can trap 80 times the heat of carbon dioxide during its lifespan, making it much more damaging to the climate short-term. 

"We should be doing anything we can to trim the rate of warming," Howarth said. "We can do a lot of damage in the next few years. You actually run the risk of irreversible, catastrophic warming."