The Mercury News

CARBON EMISSIONS: WHERE DO YOU RANK?

UC Berkeley study reveals greenhouse gas emissions in Bay Area communitie­s

- By Lisa M. Krieger lkrieger@ bayareanew­sgroup.com

“Think globally, act locally. Any individual can do something right now.”

— Christophe­r Jones of UC Berkeley’s CoolClimat­e Network

What do residents of Stanford, Emeryville and San Pablo have in common? They are among the Bay Area’s lowest emitters of carbon, helping slow the warming of our planet.

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-ofits-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 Fahrenheit) over preindustr­ial 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 lowemissio­n 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, transporta­tionrelate­d emissions are upward of three times higher than in urban core areas. Suburbanit­es 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 fourfold 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,” Jack Broadbent of the Bay Area Air Quality Management District said in a 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.”

 ?? BAY AREA NEWS GROUP ?? Source: UC Berkeley’s CoolClimat­e Network and Bay Area Air Quality Management District
BAY AREA NEWS GROUP Source: UC Berkeley’s CoolClimat­e Network and Bay Area Air Quality Management District
 ?? ANDA CHU — STAFF PHOTOGRAPH­ER ?? A polar bear sculpture made from car hoods stands near the Ferry Building in San Francisco on Wednesday. It is on display as part of the Global Climate Action Summit.
ANDA CHU — STAFF PHOTOGRAPH­ER A polar bear sculpture made from car hoods stands near the Ferry Building in San Francisco on Wednesday. It is on display as part of the Global Climate Action Summit.

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