Study says leaking natural gas has a negative environmental impact

As natural gas production increases around Colorado and the nation, new research from the Department of Civil Engineering shows that it can have a similar impact on climate change as coal if it’s allowed to leak while producing electricity.

“Reducing greenhouse gas emissions is one of the grand challenges of our time,” said David Mays, associate professor of civil engineering. “A large fraction of greenhouse gas emissions come from electrical generating plants, which are largely fueled by coal. Natural gas has the potential to produce electricity with about half the greenhouse gas emissions of coal.”

Recent advances in hydraulic fracturing and drilling have increased natural gas production. But between 70 and 90 percent of that gas is methane, a potent greenhouse gas, so any leakage severely undermines natural gas’s potential as a bridge fuel to help the country move away from coal.

In collaboration with Mays, Nicolas Sanchez, a recent civil engineering graduate (MS ’14), asked the question “How much leakage is required to eliminate the carbon advantage of natural gas over coal for generating electricity?” Their study examined the rate of natural gas leakage that rendered its greenhouse gas footprint equivalent to that of coal when it comes to producing electricity.

The results show that over a 20-year period, a leakage rate of 3.9 percent renders natural gas as damaging as coal when it comes to climate change. Leakage becomes less critical over a span of 100 years, when a leakage rate of 9.1 percent gives natural gas the same environmental impact as coal.

In summary, electricity made from natural gas has about half the greenhouse gas footprint as electricity produced from coal, as long as there is no methane leakage in the process of producing the power. However, any gas leak swiftly increases the carbon footprint and must be controlled if natural gas is to offer any significant advantage over coal, said Mays.

“This study is important because it shows that controlling natural gas leakage is crucial at every step of the supply chain, from drilling to residential distribution,” he said.