The Calgary Urban Methane Emissions Measurement Testbed (CURMET) Project

Urban methane emissions represent a large yet poorly constrained component of national greenhouse gas budgets. Their characterization is challenging because emissions arise from a complex mix of known sources and a large population of small, spatially distributed, and often intermittent emitters embedded within dense and heterogeneous urban infrastructure. These diffuse emissions complicate measurement, source attribution, and scaling from individual components to the city scale. To address this challenge, we initiated the Calgary Urban Methane Emissions Measurement (CURMET) Testbed (www.curmet.ca), a major Canadian research initiative aimed at quantifying urban methane emissions across spatial scales and identifying the dominant contributors in a large Canadian city. 

The CURMET Project integrates satellite, drone, vehicle-based, human-portable, and component-level measurements with new analytical and modeling approaches to constrain methane emissions across spatial and temporal scales. Satellite-based analyses using TROPOMI provide independent, top-down estimates of Calgary’s total methane emission rate, placing bounds on city-scale fluxes. Extensive vehicle-based surveys resolve methane enhancements from neighborhood to individual infrastructure scales, enabling source localization, attribution, and the identification of actionable emission hotspots. These surveys directly supported mitigation through the detection and subsequent abatement of several large fugitive sources during the project. Targeted measurements of sewers, natural gas meters, natural gas distribution facilities, landfills, and wastewater treatment plants further provide source-level emission estimates that inform prioritization and evaluation of mitigation efforts. 

Key advances from CURMET demonstrate the effectiveness of vehicle-based monitoring for detecting and prioritizing urban methane sources, and the value of geochemical source disambiguation for separating dominant source categories. Early results from Calgary indicate that emissions from natural gas dominate the city’s methane budget, contrasting with research in other Canadian cities where landfills are estimated to be the dominant sources of methane emissions. Methodological developments include a human-portable flux plane technique for quantifying facility-scale emissions, and the deployment of robotic and e-bike–mounted systems to measure emissions in areas inaccessible to conventional vehicles or requiring enhanced maneuverability. 

CURMET results create an empirical basis for urban methane mitigation by distinguishing persistent, episodic, and negligible sources across the city. By linking city-scale fluxes with source-resolved measurements, the project supports targeted mitigation actions, improved emissions inventories, and verification of mitigation effectiveness. These outcomes illustrate how integrated urban measurement programs can directly inform cost-effective methane reduction strategies and support municipal, provincial, and national climate policy.