A Cessna plane flies over an atmospheric radiation measurement tower. It's making continuous observations of carbon dioxide near the town of Lamont, Okla. 

(Photo: Courtesy of Lawrence Berkeley National Laboratory/Roy Kaltschmidt)
According to a recent Harvard study, methane emissions could be two to five times higher than the EPA has been reporting.

Colm Sweeney is an atmospheric scientist at CU-Boulder and he co-authored the study.

He spoke to CPR’s Lesley McClurg about why the EPA could be underestimating how much methane is in the air. 

THE BOTTOM LINE: If methane is leaking at high levels from oil and gas production then drilling for natural gas isn't greener than coal.