Natural gas leaks are greater than predicted

Most Americans already know that their energy use results in pollution, but they  may not know the extent of the pollution. A recent National Oceanic & Atmospheric Organization (NOAA) study shows that not even scientists are fully aware of the amount of pollution released from natural gas wells in Colorado.
The study, led by NOAA atmospheric scientist Gabrielle P??tron, concluded that natural gas wells have leaked twice as much gas as Environmental Protection Agency (EPA) scientists had previously predicted.
Natural gas is used as a fuel alternative to coal because it releases less carbon dioxide. Before it can be used as a fuel, natural gas has to go through a processing stage, which releases methane. Methane is a gas that plays a large role in warming the Earth's atmosphere. There are about 18,000 to 20,000 natural gas wells in Weld Country in Northeastern Colorado, which is where the study was conducted.
P??tron and her team tracked air composition by taking weekly air samples from their towers set up around the world. They started measuring at one of their tall towers in Colorado in 2007. Their measurements tracked the amount of gases such as methane, propane, butane, pentane and benzene in the air.
"We tracked the air composition around the world and over the continent in the US by grabbing air samples weekly at our global network and daily at our network that's over the continental US," P??tron said.
The team noticed that the data from the tower in Weld County consisted of a different composition of chemicals than the data from other towers throughout the country. They found a correlation between the previously mentioned gases - as the amount of one gas increased, so did that of the others. After collecting the data, the researchers tried to find the cause of the emission of all five of those compounds.
By analyzing wind patterns, they found that these chemicals were coming from Weld County. They took air samples from Weld County in areas close to known methane sources and found equal amounts of the five chemicals.
Their results proved that the natural gas wells had caused the increase in these chemicals. The EPA had previously thought that natural gas wells had leaked one to two percent of their methane. The measurements from this study, however, show that these natural gas wells are leaking four percent of their methane.
The recorded methane concentrations are not only from the wells themselves but also from natural gas processing plans and compression stations. "When we say that the leak rate is twice what's reported in inventories, it's the leak rate for the entire infrastructure, not only the [wells]," P??tron said.
According to Hopkins Earth and Planetary Sciences Assistant Professor Benjamin Zaitchik, this study is important because it focuses on methane, which has very powerful short-term warming effects.
He thinks that this study may cause some to question whether natural gas is a viable alternative to coal-based energy. "Natural gas was such good news for the U.S. . .it's good for natural security, it's good for rural economies and it's good for climate, and now maybe [it's] not," Zaitchik says.
She hopes that her study will increase awareness about how emissions are able to change from one area to another and show that these emissions need to continue to be studied.
This study will help policy makers, such as the EPA, know exactly what gases and energy sources to target. However, P??tron emphasized that her study was not trying to denounce using natural gas as an energy source, as it did not go as far to study the effects of this extra methane in the atmosphere.
"We're not pushing any judgment on which fossil fuel is better than the other," she says. "Our study is [just] making a clearer picture of all of this."
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