Using satellites to uncover large methane emissions from landfills

Area of Science:

• Environmental Science
• Atmospheric Science
• Remote Sensing

Background:

• Atmospheric methane concentrations are rising rapidly, necessitating identification of key emission sources.
• Landfills are significant contributors to methane emissions, yet facility-level data is often lacking.

Purpose of the Study:

• To demonstrate a synergistic satellite approach for detecting and quantifying methane emissions from individual landfills.
• To identify and analyze methane superemitters in major urban areas.

Main Methods:

• Utilizing the Tropospheric Monitoring Instrument (TROPOMI) for global methane hot spot detection.
• Employing high-resolution GHGSat observations for facility-level emission identification and characterization.
• Applying TROPOMI data inversion to assess city-level emissions and landfill contributions.

Main Results:

• Strongly emitting landfills (3-29 t/hr) were detected in Buenos Aires, Delhi, Lahore, and Mumbai.
• City-level methane emissions were found to be 1.4 to 2.6 times higher than reported in inventories.
• Landfills accounted for 6% to 50% of the identified city-level methane emissions.

Conclusions:

• Complementary satellite data fusion enables effective global monitoring of methane superemitters.
• Facility-level emission data from landfills is critical for accurate emissions inventories and mitigation strategies.
• This methodology supports targeted methane emission reduction efforts worldwide.