Methane emission from abandoned wells Available to Purchase

Per kilo, atmospheric methane is about 34 times as potent a greenhouse gas as carbon dioxide is. Whether natural or anthropogenic, sources of CH₄ can therefore have a big impact on radiative forcing. Mary Kang of Princeton University and her colleagues have quantified one previously unaccounted source of atmospheric CH₄: abandoned oil and gas wells. Estimates put the number of such wells in the US at 3 million. In her study, Kang focused on 19 wells in the region where oil and gas were first extracted in the US: Western Pennsylvania. She and her colleagues placed enclosing chambers over the wellheads, like the one shown here, and measured the methane flux. They repeated the procedure at control sites near the wells. On average, the methane flux per well was 11 000 mg/h, whereas the mean flux per control site was 0.19 mg/h. Oil and gas extraction...