Direct Methane Removal from Air by Aerobic Methanotrophs

Abstract

The rapid pace of climate change has created great urgency for short-term mitigation strategies. Appropriately, the long-term target for intervening in global warming is CO₂, but experts suggest that methane should be a key short-term target. Methane has a warming impact 34 times greater than CO₂ on a 100-year timescale, and 86 times greater on a 20-year timescale, and its short half-life in the atmosphere provides the opportunity for near-term positive climate impacts. One approach to removing methane is the use of bacteria for which methane is their sole carbon and energy source (methanotrophs). Such bacteria convert methane to CO₂ and biomass, a potentially value-added product and co-benefit. If air above emissions sites with elevated methane is targeted, technology harnessing the aerobic methanotrophs has the potential to become economically viable and environmentally sound. This article discusses challenges and opportunities for using aerobic methanotrophs for methane removal from air, including the avoidance of increased N₂O emissions.