Methane is the major component of natural gas, which heats our homes and recently surpassed coal as the top fuel for generating electricity in the United States. But methane is also a powerful greenhouse gas that contributes to global warming. And because methane is highly flammable, gas leaks pose a significant safety hazard, as we saw in fatal explosions in 2010 in San Bruno, California and 2015 in New York City. The massive gas leak from the Aliso Canyon storage facility in Southern California in October 2015 led to evacuations of over 8,000 families after reports of serious health issues.

The United States, Canada and Mexico are working together to reduce methane emissions from the oil and gas sector through the North American Climate, Clean Energy and Environment Partnership. As one step, the U.S. Environmental Protection Agency (EPA) recently finalized rules that require oil and gas companies to adopt leak detection and repair programs.

EPA recommends that gas companies use infrared cameras, one of the most commonly available leak detection technologies. These cameras enable gas leaks to be detected rapidly and safely. Although other detection technologies are available, they’re either expensive, slow or unsuitable.

My research focuses on evaluating leak detection technologies and using those insights to inform emissions mitigation policy. In our most recent work, we analyzed the limits of infrared cameras in effectively detecting methane leaks. Some of these limitations have important policy implications.

Cameras work better in some conditions than others

Infrared cameras work much like an iPhone camera, with a key difference. While an iPhone camera is sensitive to visible light, infrared cameras are sensitive to infrared light, the portion of the sun’s light that is invisible to the naked eye and has wavelengths longer than red. Since methane is sensitive to infrared light, infrared cameras can detect it. Indeed many production facility operators use them routinely for leak detection and repair procedures, with anecdotal success.

Despite such evidence, there were no systematic studies on the effectiveness of these cameras. And because all objects emit infrared light, we suspected that environmental conditions might play an important role in how the camera works. In the study I coauthored, we analyzed how environmental factors like temperature, wind, humidity and background conditions affected what the camera “sees.”