Top-Down Quantification of Methane Emissions from California's Natural Gas System

Identifying the main source of methane emissions is the first step to develop sound mitigation options.

The Regents of the University of California on behalf of the Davis Campus


Davis, CA

Recipient Location


Senate District


Assembly District



Amount Spent



Project Status

Project Result

The research team measured methane emissions associated with production sites in the south part of the San Joaquin Valley; underground storage facilities in the Sacramento- San Joaquin Delta; the distribution system in Bakersfield, Sacramento, and Oakland; a handful of abandoned wells; and approximately 10 homes. The results suggest that most of the emissions are coming from production wells and the distribution system. Emissions from homes are relatively small but significant. The discovery of end-use emission from this study lead to multiple future studies to understand the significance of emissions from building and residential sectors.

The Issue

The natural gas system is composed of different parts: production wells, processing units, transmission, distribution, and final consumption. It is unclear the relative contribution of these parts of the natural gas system to total methane emissions. It is important to identify the main source of emissions (e.g., natural gas wells) to develop mitigation options to reduce overall emissions.

Project Innovation

The purpose of this project is to quantitatively survey methane emissions from key subsectors of the natural gas system including production, processing, transmission and distribution, and end-uses in homes. Four field campaigns were planned for this project. The first took place in November 2013. The field campaigns included a research aircraft, a mobile platform, and other measurement techniques.

Project Benefits

Researchers have reported that actual methane emissions from the natural gas system may be much higher than expected. However, emission estimates from the natural gas system are highly uncertain. This research will help provide a more accurate and comprehensive accounting of methane emissions from the natural gas sector.

Environmental & Public Health

Environmental Sustainability

Identifying the main sources of methane emissions from the natural gas system will allow the development of cost effective mitigation measures.

Key Project Members

Project Member

Marc Fischer



Lawrence Berkeley National Laboratory


San Jose State University


University of California, Irvine


Picarro, Inc.


Contact the Team