Portola Valley, Piedmont and Alamo residents have a more dubious distinction, ranking at the top of carbon emitters, according to a UC-Berkeley analysis that offers a stark revelation of how each Bay Area neighborhood contributes to global warming.
As mayors from around the world commit to climate action plans this week at San Francisco’s Global Climate Action Summit, the first-of-its-kind interactive map exposes our local winners and losers in the race to limit the increase in warming to 1.5 degrees Celsius (or 3.6 degrees Farenheit) over pre-industrial levels, by 2020. It quantifies communities’ carbon footprint — the total amount of greenhouse gas emissions that come from transportation, energy use and other sources. The gases trap heat in the atmosphere, causing global warming.
The map covers census block groups – neighborhoods of several hundred to a few thousand households – in the nine-county Bay Area. Neighborhoods with relatively high emissions show up as red, while low-emission neighborhoods are green.
The researchers calculated the carbon footprints based on household consumption, regardless of where on the globe emissions occurred. For example, if a computer was made in China but bought by a Berkeley resident, all emissions from the production of the computer were allocated to the Berkeley neighborhood.
Because transportation is such a large source of emissions, some neighborhoods have footprints three or four times larger than others, said Christopher Jones of UC Berkeley’s CoolClimate Network and lead author of the study, sponsored by the Bay Area Air Quality Management District. The calculation is based on use of cars, trucks and other gas-powered vehicles by the residents in a particular neighborhood.
The research, published online, can be used to target policies and programs to help similar communities speed up their adoption of carbon-efficient technologies, said Jones, 47, a Davis resident who rides his bike to work and shares an electric car with his wife.
For example, some communities could build more environmentally friendly, high density housing near transit while others could install more solar panels or encourage a switch to electric cars.
The best way to reduce emissions in the Bay Area is to massively scale up electrification of our vehicles and our heating, said Jones. Those changes would reduce most cities’ carbon footprint by 30 percent, he said.
“Our goal,” he said, “is to provide the resources to local residents and governments to understand which options have the most potential to reduce greenhouse gas emissions — and what matters least.”
Cities are critical to the effort. Although they represent just two percent of the world’s land area, they account for more than 70 percent of carbon pollution.
In the Bay Area, transportation is the largest source of households’ emissions, representing 33 percent of the total, the team found. That was followed by food (19 percent), goods (18 percent), services (18 percent), heating fuels (5 percent), home construction (3 percent), electricity (2 percent) and waste (1 percent).
But in some urban cores like Oakland, where emissions from transportation are low, meat consumption contributes roughly an equivalent amount as vehicles, the researchers found, because livestock farming produces large amounts of greenhouse gases.
In suburban cities, such as Alamo, transportation-related emissions are upward of three times higher than in urban core areas. Surbanites tend to emit more greenhouse gases because they own more cars and larger homes, Jones said. Urban residents, on the other hand, tend to drive less and live in smaller homes and apartments. At Stanford, for instance, many students and faculty walk or bicycle to class.
But even within the same city there are marked differences. For instance, average emissions per household in West Oakland were nearly four-fold lower than emissions in the wealthier Oakland Hills.
“(The analysis) provides the bigger picture of how goods and services consumed by each of us in the Bay Area contribute to climate change and, by extension, highlights opportunities to reduce those emissions,” said Jack Broadbent of the Bay Area Air Quality Management District, in a prepared statement.
While the 2015 Paris climate summit attained landmark national commitments for greenhouse gas reductions, much of the hard work of reducing emissions falls on cities to change their residents’ behavior.
The Berkeley researchers said the maps can be used to tailor the carbon reduction campaigns for different neighborhoods. For example, they can be used by city planners to pinpoint the best areas and designs for new housing. Population-dense neighborhoods contribute fewer emissions per household, so urban infill can reduce a region’s overall footprint.
And technology-oriented strategies — such as all-electric homes and cars — could help affluent suburban jurisdictions with large houses, big rooftops, and long commutes by car.
Households in less-affluent, high-density urban neighborhoods don’t consume as much energy, and don’t have the roof space, or budgets, to install solar panels. So these residents would be better candidates for campaigns to promote healthy diets and sustainable consumption.
The team also has published an online, interactive map of carbon footprints by ZIP code for the entire country. While California has relatively low emissions associated with household electricity, the opposite is true in parts of the Midwest, where electricity is produced largely from coal, they found.
If the Bay Area wants to cut emissions quickly and meet the climate goals laid out in the Paris Agreement, communities should start now, Jones said.
“Think globally, act locally,” Jones said. “Any individual can do something right now.”
©2018 the San Jose Mercury News (San Jose, Calif.) Distributed by Tribune Content Agency, LLC.
