Flaring is widely used by the fossil fuel industry to dispose of natural gas. Industry and governments generally assume that flares remain lit and destroy methane, the predominant component of natural gas, with 98% efficiency. Neither assumption, however, is based on real-world observations. We calculate flare efficiency using airborne sampling across three basins responsible for >80% of US flaring and combine these observations with unlit flare prevalence surveys. We find that both unlit flares and inefficient combustion contribute comparably to ineffective methane destruction, with flares effectively destroying only 91.1% (90.2, 91.8; 95% confidence interval) of methane. This represents a fivefold increase in methane emissions above present assumptions and constitutes 4 to 10% of total US oil and gas methane emissions, highlighting a previously underappreciated methane source and mitigation opportunity.

中文翻译：

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低效和未点燃的天然气火炬都排放大量甲烷

燃烧被化石燃料工业广泛用于处理天然气。工业界和政府通常认为火炬保持点燃并以 98% 的效率破坏甲烷（天然气的主要成分）。然而，这两个假设都不是基于现实世界的观察。我们使用对美国 80% 以上燃烧的三个盆地的空中采样计算燃烧效率，并将这些观察结果与无照明燃烧流行率调查相结合。我们发现，未点燃的火炬和低效燃烧对甲烷的无效破坏贡献相当，火炬仅有效破坏了 91.1%（90.2，91.8；95% 置信区间）的甲烷。这表示甲烷排放量比目前的假设增加了五倍，占美国石油和天然气甲烷排放总量的 4% 到 10%，