Structural shifts in China's oil and gas CH emissions with implications for mitigation efforts.

Methane (CH) is a potent and short-lived climate pollutant, with the oil and gas sectors emerging as an important contributor. China exhibited a substantial expansion of oil and gas infrastructures over recent years, but the CH emission accounting tends to be incomplete and uncertain. Here, we construct a CH emission database of China's oil and gas systems from 1990-2022 with 80% of emissions tracked as refineries, facilities, pipelines, and field sources. Results show that China's oil and gas CH emissions have risen from 0.5[0.5-0.6] TgCH yr in 1990 to 4.0[3.7-4.4] TgCH yr in 2022, primarily driven by the growing demand for natural gas during the energy transition. The spatial details provided are critical for characterizing emission hotspots, especially in unconventional gas production fields and densely populated eastern regions. This long-time series and spatially explicit CH emission database can contribute to informed policy decisions and swift climate action.