Scaling Urban Methane Emissions: Utility of Single-Site Measurements in Five Urban Domains

Published

July 9, 2025

Author(s)

Kimberly Mueller, Anna Karion, Julia Marrs, Israel Lopez Coto, James Whetstone, Vineet Yadav, Genevieve Plant, Zachary Barkley

Abstract

Methane (CH4) emissions from urban areas remain poorly understood, in part because they cannot be directly observed. Current understanding predominantly relies on inventory-based approaches, which often involve assumptions about emission factors and activity data or downscaling methods. These inventories frequently underestimate emissions, as evidenced by urban studies showing emissions exceeding inventory estimates by a factor of 2 to 3 in U.S. and European cities. Satellite observations and mobile platforms have been used to improve urban CH4 estimates but face challenges such as coarse spatial resolution, number of observations, temporal limitations, etc. In contrast, fixed in-situ measurements calibrated to World Meteorological Organization (WMO) standards provide high-precision, continuous data, making them valuable for understanding CH4 emissions, despite spatial limitations due to the cost and logistical challenges of deploying dense networks. This study leverages in-situ observations from a single fixed site in each of five urban domains in the northeastern U.S. to estimate total urban CH4 emissions using a Bayesian scaling factor framework. The method provides robust emission estimates, consistent with other published results, while addressing spatial constraints, i.e. the lack of multiple observational sites. Proxy variables, including residential natural gas usage, population, and infrastructure characteristics, are used to explore correlations with inferred emissions, revealing critical insights into the drivers of urban CH4 emissions. For example, the results demonstrate that residential building volume is a stronger predictor of emissions than population in some regions, reflecting urban-specific factors such as infrastructure age and composition. The study highlights the importance of robust, traceable measurement frameworks and tailored proxies for accurately characterizing urban CH4 emissions. By pioneering a scalable single-site method, this work contributes to addressing critical gaps in urban CH4 monitoring, emphasizing its potential for widespread application across diverse urban settings.

Citation

Environmental Science & Technology

Volume

59

Issue

28

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.est.5c03844

Local Download

Keywords

measurements, in-situ, urban, cities

Citation

Mueller, K. , Karion, A. , Marrs, J. , Lopez Coto, I. , Whetstone, J. , Yadav, V. , Plant, G. and Barkley, Z. (2025), Scaling Urban Methane Emissions: Utility of Single-Site Measurements in Five Urban Domains, Environmental Science & Technology, [online], https://doi.org/10.1021/acs.est.5c03844, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959628 (Accessed July 31, 2026)

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