Year-long blind test finds AI methods behind most false alarms in satellite methane detection

A study published Oct. 14 in Nature ran a year-long, single-blind test of space-based methane detection: 481 metered methane releases in Arizona and 265 blank controls, timed to overpasses by 12 government, commercial and non-profit satellites, with 15 analysis teams from nine countries producing more than 2,250 estimates. Instruments built to target methane detected 92–100% of releases with false positive rates of 0–11%, while repurposed instruments detected 62–88% and broad land scanners detected poorly at the tested rates. The authors say artificial intelligence-based methods show promise but warrant caution, since 79% of false positives came from those methods, and that cloud cover above 20% degraded performance across systems.