Emissions of methane from the industrial sector have been vastly underestimated, researchers from Cornell University and Environmental Defense Fund have found.

Using a Google Street View car equipped with a high-precision methane sensor, the researchers discovered that methane emissions from ammonia fertilizer plants were 100 times higher than the fertilizer industry’s self-reported estimate. They also were substantially higher than the Environmental Protection Agency (EPA) estimate for all industrial processes in the United States.

“We took one small industry that most people have never heard of and found that its methane emissions were three times higher than the EPA assumed was emitted by all industrial production in the United States,” said John Albertson, co-author and professor of civil and environmental engineering. “It shows us that there’s a huge gap between a priori estimates and real-world measurements.”

The researchers’ findings are reported in “Estimation of Methane Emissions From the U.S. Ammonia Fertilizer Industry Using a Mobile Sensing Approach,” published in Elementa.