EVs are lowering Bay Area's carbon footprint

April 4, 2024

 Mike Bird via Pexels.

Electrification of passenger vehicles in the Bay Area is slowly driving down CO2 emissions, though not enough to meet the state's ambitious climate goals. Photo: Mike Bird via Pexels.

An extensive CO2 monitoring network set up around the San Francisco Bay Area by an atmospheric chemist from the University of California, Berkeley, has recorded the first evidence that the adoption of electric vehicles is measurably lowering the area's carbon emissions.

The network of sensors, most of them in the East Bay, is the brainchild of Ronald Cohen, UC Berkeley professor of chemistry, who envisions inexpensive, publicly funded pollution and carbon dioxide monitors widely distributed around urban areas to pinpoint emission sources and the neighborhoods most affected. An estimated 70% of global CO2 emissions come from cities, yet few urban areas have granular data about where those emissions originate.

In 2012, Cohen began setting up a Bay Area sensing network that has now grown to more than 80 stations, including seven in San Francisco, that stretches from Sonoma County through Vallejo and down to San Leandro.

Between 2018 and 2022, 57 of the sensors in the Berkeley Environmental Air Quality and CO2 Network (BEACO2N) recorded a small but steady decrease in CO2 emissions — about 1.8% annually — that translates to a 2.6% yearly drop in vehicle emission rates. Looking at California data for electric vehicle adoption — which is very high in the Bay Area — Cohen and graduate student Naomi Asimow concluded that the decrease was due to passenger vehicle electrification.

"That's 2.6% less CO2 per mile driven each year," said Asimow, who is in the Department of Earth and Planetary Science.

BEACON Map. Naomi Asimow and Ronald Cohen, UC Berkeley.

A map showing the locations of the 57 sensor nodes of the BEACO2N network that were used in this study. The network now consists of more than 80 nodes.

Map: Naomi Asimow and Ronald Cohen, UC Berkeley.

A BEACO₂N node. Ron Hipschman/Exploratorium.

A BEACO2N node, consisting of a CO2 sensor and an air quality monitor, atop the Exploratorium, an innovative science museum in San Francisco. During normal operation, the transparent cover is replaced by an opaque lid.

Photo: Ron Hipschman/Exploratorium