These satellite images show concentrations of nitrogen dioxide (a noxious gas emitted by motor vehicles, power plants, and industrial facilities) in China from January 1 to 20 (on the left) and February 10 to 25 (on the right). Evidence suggests the reduction is at least partially due to coronavirus-related quarantine measures and the ensuing economic slowdown. Images courtesy NASA.

The environmental effects of the massive shutdown in the Bay Area could offer a “teachable moment.” This catchphrase, indicating a positive view of an unexpected and perhaps upsetting event, isn’t totally applicable, because there is no designated teacher. However, there are many students, all trying to determine what the lessons may be — so perhaps this is really a “learning moment.”

Lesson One
In many places, from Venice to Delhi to Yosemite, shutting down business and travel made an immediate difference to the environment. Reports and anecdotes popped up worldwide, along with startling and unusual photographs of clear skies in Beijing, clean water in Venice, and emboldened wildlife in Wales. These showed that a world without so much human activity, particularly industrial and transportation activity, can become almost parklike in a remarkably short period of time.

This is important not just for the global environment, but on a personal level — in India, doctors reported a drop in asthma attacks, and recent studies from Harvard and the University of Bologna have demonstrated that long-term exposure to air pollution can create a greater vulnerability to COVID-19.

Lesson Two
Impacts on Bay Area air quality are harder to assess. While similarly striking pictures show improvement in April compared to the same date last year, the Bay Area Air Quality Management District has emphasized that weather plays a role, and April rainstorms helped in 2020.

Although it is too early for solid data on the shutdown impacts, the UC Davis Road Ecology Center estimated a 75 percent drop in traffic statewide from the middle of March to early April, and numbers from the Metropolitan Transportation Commission showed a 50 percent drop in bridge crossings by the end of March. The Air District has estimated that with a 70 percent decrease in traffic, particulates would decrease by 29 percent and very fine particulates by 20 percent. Nitrous oxides would drop by 38 percent and carbon dioxide by 26 percent.

Real-time data gathered by San Francisco-based company Aclima, which does hyperlocal air monitoring at street level, showed “a decided change” in traffic-related pollution, according to Chief Scientist Melissa Lunden. Aclima saw regional decreases for four of five air pollutants compared to the same weeks in 2017, 2018, and 2019. In addition, West Oakland had a significant drop in CO2 as compared to the region as a whole; this community is normally heavily impacted by transportation due to its location, but the recent levels were close to those experienced in Half Moon Bay.

Lesson Three
In the near future, there will be a “new normal.” Ideally, it will incorporate some changes based on new knowledge. The transition period toward this new normal provides an opportunity to evaluate systems and programs that help maintain patterns of travel and behavior contributing to cleaner air. At the April meeting of the Air District’s Climate Change Committee, Deputy Air Pollution Control Officer Greg Nudd asked, “Are some of these behaviors permanent, or can we make them partially permanent?”

Lunden characterized the shutdown as “an experiment we kind of backed into,” and told the Monitor that “it has provided a signal from the data. We’re no longer just modeling. If we can electrify some of the fleet — cars, vans, trucks — we can now see what our pollution levels would be.”

For consumers, choosing electric vehicles and cleaner air will be weighed against less expensive gas-fueled vehicles, cheaper gas, and a surplus of used vehicles due to lease and loan problems. There is also the possibility that some people simply decide to drive less.

In the Bay Area, one indicator that drivers may still be open to moving to electric vehicles is the consistent response to the Air District’s Clean Cars for All incentive program. Rebecca Fisher, the agency’s acting manager for electric vehicle outreach and partnerships, reported that applications for March and April 2020 were keeping pace with the previous rate of more than 100 applications per month. Fisher commented, “Grants for income-qualified residents are even more important now as households grapple with the economic downturn and look for a stable and reliable way to get to work.”

Applicants with eligible vehicles who meet income limits can receive up to $9,500 from Clean Cars for All toward the purchase of a new or used electric vehicle, and up to $2,000 for home charging equipment. (New non-driving options for Clean Cars for All grants include public transit cards and electric bicycles.) The program is one of a number of electric vehicle incentive programs funded by state and regional agencies and local electric utility districts, some of which can be combined. Fisher observed, “We have seen some people getting into a used electric vehicle with no money down.”

“Getting people into [electric vehicles] is absolutely critical for meeting our climate goals,” Nudd told the Air District committee. He added, “It’s what I call necessary but not sufficient — we also have to do trip reduction. A lot of the particulate emissions from vehicles are from brake and tire wear, and road dust.”

Trip reduction depends heavily on people either not traveling or using transit for their trips. Nudd suggested, “One of the things we think is particularly attractive is telework, and the Bay Area is particularly well-suited to telework.” The Air District is asking local companies to include telework options as part of the Bay Area Commuter Benefits Program. Santa Clara County is analyzing expanding telework for county employees. It will be working with the Air District, employers, and transit agencies to increase telecommuting in the county and to encourage workers who must commute to utilize transit. The Air District is also expanding remote work options for its own employees, and will begin developing a model remote work policy for public agencies.

Some large employers already plan to delay workers’ return to offices. Depressed employment levels may also reduce commute trips. But if people do travel, will they go back to transit?

An evaluation of transit recoveries from disasters by the Mineta Transportation Institute concluded that how quickly riders return to transit “depends on how much they need it.” For example, “transit riders are frequently low-income women of color who are still traveling to work to provide essential services,” according to a UCLA webinar on women and transit. Ben Fried from TransitCenter, an advocacy group, told CNN that “riders need to feel safe,” specifying adequate cleaning and riders wearing masks.

Transit agencies expect a struggle to serve riders if the pandemic recovery drags out or falters. A loss in revenue could mean equally large cuts to service, limiting the mobility of some riders and pushing others into cars. In the Bay Area, with traffic chokepoints and some transit-dependent communities like San Francisco, this could mean gridlock, according to a recent Vanderbilt University study, which predicts that low transit ridership could add up to 40 minutes to a commute. This would push pollution levels back up.

Lesson Four
Money may decide how much things change. Transit bail-outs and clean car incentives are two components of a cleaner recovery that will need financial support, but budgets at all levels promise to be tight. Part of the increase in delivery services has been using personal vehicles, so clean cars can help, but Clean Cars for All is funded by cap-and-trade revenues, which may be affected by the economic downturn.
Boris Quennehen, an atmospheric scientist, explained in Forbes that because trucks aren’t as clean as cars, “a decrease in car traffic as a result of stay-at-home measures can easily be offset by a slight increase in deliveries and truck traffic.” A switch to electric trucks is on the California Air Resources Board agenda; truckers say that now is not the time to impose new requirements, and the state may not be able to afford the incentives either.

Climate scientist Katherine Hayhoe told PBS in mid-April, “We have not achieved those [environmental changes] today through sustainable methods. People have to return to work, children need to return to school, the economy needs to start back up. But if we had that economy powered by clean energy, that is what our skies, our water, and our land would look like.” Bay Area residents have seen it, perhaps briefly, but will they make the effort to sustain it? And who will pay for it?

Leslie Stewart covers air quality and energy for the Monitor.