Using satellites to uncover large methane emissions from landfills

Abstract

As atmospheric methane concentrations increase at record pace, it is critical to identify individual emission sources with high potential for mitigation. Here, we leverage the synergy between satellite instruments with different spatiotemporal coverage and resolution to detect and quantify emissions from individual landfills. We use the global surveying Tropospheric Monitoring Instrument (TROPOMI) to identify large emission hot spots and then zoom in with high-resolution target-mode observations from the GHGSat instrument suite to identify the responsible facilities and characterize their emissions. Using this approach, we detect and analyze strongly emitting landfills (3 to 29 t hour −1 ) in Buenos Aires, Delhi, Lahore, and Mumbai. Using TROPOMI data in an inversion, we find that city-level emissions are 1.4 to 2.6 times larger than reported in commonly used emission inventories and that the landfills contribute 6 to 50% of those emissions. Our work demonstrates how complementary satellites enable global detection, identification, and monitoring of methane superemitters at the facility level.

Global warming will largely increase CH4 emissions from waste treatment: insight from the first city scale CH4 concentration observation network in Hangzhou city, China

“…However, few studies in China and worldwide have performed atmospheric inversions for city-scale waste treatment especially by using tower-based observations, which can present an independent evaluation method. the EDGAR inventory, where emissions from landfills accounted for 6~50% of total emissions (Maasakkers et al, 2022). In our study, we found that the annual waste A few observation-based measurements have been conducted for waste treatment but only at specific sites with large discrepancies in EFs (Du et al, 2017;Cai et al, 2018;NBSC, 2015;Wang et al, 2015;Florentino et al, 2010;Tolaymat et al, 2010;Cai et al, 2014;.…”

“…Although some progress has been made in measuring site-scale CH4 emissions from waste treatment, the estimated emissions still show large discrepancies owing to many factors, such as the amount of waste and its composition, meteorological conditions, such as temperature and water content, proportion between landfills and incineration, degradable organic carbon ratio, CH4 oxidation efficiency, and landfill gas collection (Masuda et al, 2018;Cai et al, 2018;Hua et al, 2022;Bian et al, 2022;Maasakkers et al, 2022). Furthermore, CH4 emissions from sewage and landfills are caused by microbial process, especially methanogens, and their emission factors (EFs) are highly sensitive to temperature.…”

“…Furthermore, large temperature-induced monthly variations should occur in waste treatment CH4 emissions; however, almost all satellite-based inversions were conducted at an annual scale without seasonal variations. Only one recent study was based on satellite observations and focused on urban waste treatment CH4 emissions, and it found that annual total CH4 emissions from four cities were 1.4 to 2.6 times larger than inventories in India and Pakistan, where landfills contributed to 6~50% of total emissions and indicated a large bias in our understanding of waste treatment CH4 emissions (Maasakkers et al, 2022).…”

Automated detection and monitoring of methane super-emitters using satellite data

“…dysfunctional natural gas flaring systems (Irakulis-Loitxate et al, 2022a, b;Plant et al, 2022). Super-emitters are not limited to oil and gas production but also occur in the coal mining and waste sectors (Cusworth et al, 2020;Sadavarte et al, 2021;Maasakkers et al, 2022b). Detection, localization, and global monitoring of these methane super-emitters provides a large opportunity to reduce emissions (UNEP and CCAC, 2021;Parry et al, 2022).…”

“…Varon et al (2021) demonstrated that the Multi-Spectral Instrument, a band imaging instrument onboard the Sentinel-2 satellite (Drusch et al, 2012), is capable of retrieving large methane plumes with a pixel resolution of 20 m for continuous, 290 km wide swaths over favorable terrain. TROPOMI's daily global coverage is particularly well suited to guide observations of these high-resolution instruments, that often have limited viewing domains, to identify large sources of methane at facility level (Irakulis-Loitxate et al, 2022b;Maasakkers et al, 2022b). TROPOMI has collected over 5 years of methane data, which include numerous methane emission plume signals that cannot feasibly be identified manually.…”