Researchers Say Methane Leaks Are Underestimated

Leaks of methane, a potent greenhouse gas and the primary component in natural gas, are being significantly underestimated in EPA calculations used for climate-change policy decisions, according to a policy forum paper in Science (2014, DOI: 10.1126/science.1247045). The researchers examined some 200 studies done over the past 20 years and concluded that real methane leaks to the atmosphere are 1.25 to 1.75 times as high as official agency estimates. However, because of great uncertainty over individual sources, the researchers were unable to attribute the leaks with any confidence to specific sources or locations. Methane is 30 times as potent a greenhouse gas as carbon dioxide over a 100-year period, the report notes. But the report also says natural gas power plants are still cleaner than coal plants, which generate more CO₂ and other emissions. Consequently, the researchers say that despite its potency, natural gas retains a large enough greenhouse gas advantage over coal to justify its continued use as a “bridge fuel” to a cleaner future.