As part of our landmark 16-study series and ongoing work in measuring methane emissions, we previously published a paper that compared and reconciled top-down (airborne-based measurements ) with bottom-up (emissions inventory, using ground-based measurements) emissions.
This paper found that 1% of natural gas production sites accounted for 44% of total emissions from all sites, or 10% of sites 80% of emissions; emission estimates were based on facility-wide (site-based) measurements. Sites or equipment that produce disproportionate shares of total emissions are often called “super-emitters”. A big question that remained was what caused some sites to become a super-emitter; this remained a “black box” without additional knowledge about which components or operational conditions within a site could trigger the high-emissions.