Recorded on August 11, 2022

Abstract:
Methane (CH4) from oil and gas (O&G) activities is a significant contributor to climate change and recent research has highlighted the degree to which a small fraction of large emitters disproportionately contribute to total emissions. We employ a single-blind controlled methane release study design to evaluate the detection and quantification accuracy of four airplane-based methane sensing technologies (Bridger Photonics’s Gas Mapping LiDAR, Carbon Mapper’s Global Airborne Observatory, GHGSat-AV, and Methane AIR), alongside five methane-sensing satellites (GHGSat, WorldView 3, PRISMA, Sentinel-2, and Landsat 8). Release levels focus on large emitters (10-7,000+ kgh CH4). In two 2021 campaigns, metered natural gas was released concurrently with overpasses by the tested technologies. Results were submitted by operators in a three-stage unblinding process (two stages for satellites). Detection rates of non-zero releases were 100%, 85%, and 86% for Bridger, Carbon Mapper, and GHGSat, respectively. Bridger, Carbon Mapper, and GHGSat reported Stage 1 (fully blinded) quantification results with a parity slope of 1.06 (R2 = 0.78, n = 110), 0.33 (R2 = 0.35, n = 153), and 1.00 (R2 = 0.38, n = 149), respectively. In Stage 2 (on the ground anemometer wind speed data unblinded), two out of three teams significantly reduced variance in the parity slope, highlighting the importance of accurate wind data. In Stage 3 (half release volumes unblinded), improvement was mixed (one out of three teams improved both variance and bias in the parity slope). For satellites, teams correctly identified 71% of all emissions, ranging from 0.20 [0.19, 0.21] metric tons per hour (t/h) to 7.2 [6.8, 7.6] t/h. Over three-quarters (78%) of quantified estimates fell within ±50% of the metered value, comparable to airplane-based remote sensing technologies. The relatively wide-area Sentinel-2 and Landsat 8 satellites detected emissions as low as 1.4 [1.3, 1.5, 95% confidence interval] t/h, while GHGSat’s targeted system quantified an 0.20 [0.19, 0.21] t/h emission to within 13%. While the fraction of global methane emissions detectable by satellite remains unknown, we estimate that satellite networks could see 18-81% of total oil and natural gas system emissions detected in a recent survey of a high-emitting basin.

Bio:
Evan Sherwin is a data-informed energy policy analyst investigating the role of hydrocarbon fuels in a rapidly decarbonizing economy. Much of his research focuses on leveraging emerging technologies and datasets to find and fix methane emissions across the oil and gas value chain. Evan is a Postdoctoral Research Fellow at Stanford University’s department of Energy Resources Engineering with a PhD in Engineering and Public Policy and an MS in Machine Learning from Carnegie Mellon University. Evan is the founder and chair of the Methane Emissions Technology Alliance international seminar series and a founding member on the Board of Directors of Climate Change AI.