(Photo courtesy the Environmental Defense Fund)

The car used to help map where natural gas is leaking.

Americans are using a lot more natural gas than we used to, and that could pose a climate problem, according to the Environmental Defense Fund (EDF).

Four years ago, the EDF partnered with Google Earth Outreach to find out just how big that potential problem is. They’re using Google Street View cars to locate and map methane leaking from natural gas lines in cities nationwide.

Mesa, Arizona was one of the most recent cities to be mapped.

Researchers found only three small leaks, according to Mary Gade, a former environmental official working with EDF on this project. That comes out to a ratio of about one leak for every 60 miles they drove.

“That’s really excellent,” she said. “We have mapped in other cities with older, more aging infrastructure like Boston or New York City, and found one leak for every mile.”

The project was spurred by the increase in natural gas extraction in the U.S. through fracking and other methods, according to Gade. Now, we’re using more natural gas, and so the EDF wanted to understand the environmental implications of that.

“Utilities have always looked at the leaks in terms of safety,” Gade said. “To make sure that there are no explosions from natural gas leaks under city streets. But, because of our focus on climate, we were interested in how much actual methane was releasing.”

Methane is a primary component of natural gas, and it’s considered a greenhouse gas like carbon dioxide, according to the EDF. And, when it leaks from natural gas pipes, it has a warming effect that’s 84 times stronger than carbon dioxide over a 20-year period.

“Scientists think that some 25 percent of the global warming we’re currently experiencing is actually caused by methane right now,” Gade said.

According to Gade, larger leaks that can be dangerous have to be utilities’ first priority, but smaller methane leaks that don’t pose a safety hazard can go unfixed for years.

“And that poses a climate problem,” she said. But, it’s also expensive, she said, “Just wasted gas going up into the atmosphere that people are paying for.”

Lyndon Boltz, the energy resources compliance administrator for the City of Mesa, said the city utility uses different equipment to test for gas leaks and could only confirm one of the three small leaks that the EDF identified, and that one was repaired immediately.

The instrumentation EDF used to detect the leaks is not currently approved by the federal agency in charge of pipeline safety, according to Boltz.