Satellite Monitoring

We measured emissions from Calgary using the TROPOMI satellite instrument. Calgary is a small, but clear methane hot spot in satellite data. Furthermore, local hot spots within Calgary exist adjacent to known methane sources (e.g., wastewater treatment facilities and landfills) demonstrating that satellites can clearly see major urban methane sources in Calgary. While the TROPOMI satellite instrument is still insufficient resolution to provide detailed data on each individual source, it can provide an total city-level methane emissions rate for Calgary. 

Our investigation suggests that the city-level CH4 emission from Calgary was 215.4 ± 132.8 tCH4/d. This differs considerably from reported methane emissions, which are far lower. This mismatch suggests that reporting may not be accurately estimating emissions from Calgary. This noted, notable bias exists because of the limited reliable observations and temporal variability. This project helpfully provides a robust estimate of total-city Calgary emissions and demonstrates how satellite measurements can be used to benchmark urban emissions.