Private satellites are revolutionizing our ability to track methane emissions from oil, gas, and coal facilities worldwide. While carbon dioxide often takes the spotlight in discussions about greenhouse gases, methane is the second-largest contributor to human-induced global warming. A significant portion of these emissions originate from the energy sector, particularly from concentrated sources like flare stacks, coal vents, and open-pit mines. To combat this, we must identify the primary culprits, and new satellite data is proving invaluable in this endeavor.
The GHGSat constellation, managed by the Canadian company GHGSat, is a game-changer. It combines meter-scale spatial resolution with global coverage, bridging the gap between traditional measurement methods. By analyzing methane plumes observed in 2023, the team estimated annual emissions from 3,114 oil, gas, and coal facilities worldwide, totaling approximately 9 million tons (8.3 million metric tons) annually.
The satellite data clearly highlights the biggest emitters. Turkmenistan, the U.S., Russia, Mexico, and Kazakhstan are among the top contributors of oil and gas methane emissions. China and Russia are the major sources of coal emissions. However, when zooming in, the precision of bottom-up inventories diminishes. The study found moderate agreement between GHGSat-measured emissions and country-level predictions but very little agreement at a finer 0.2-degree x 0.2-degree resolution, emphasizing the need for facility-level changes.
The researchers also tracked the frequency of detectable methane plumes from individual facilities, a metric called persistence. Coal facilities emitted methane about half the time on average, while oil and gas sites were far more intermittent, emitting detectable methane in only about 16% of satellite observations. This variability poses challenges for capturing oil and gas emissions with infrequent monitoring.
To enhance accuracy and actionability, GHGSat is expanding its constellation. Recent launches have increased their satellite count to 14, improving spatial and temporal coverage. This enables more frequent emissions detection and monitoring, making detailed surveys like GHGSat's crucial for effective mitigation efforts.
