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Last week, the Bay Area's Business Council on Climate Change — which SPUR is a part of — released the Green Tenant Toolkit, an online resource for improving the sustainable performance of existing commercial buildings in San Francisco. The toolkit is designed to help commercial tenants, building owners and property managers collaborate to improve the energy efficiency and other sustainability metrics of their buildings. It is divided into three sections:

1. Green leases, including sample leases and key negotiation points in the leasing process;

2. Stakeholder engagement, which defines what the roles can be for owners, tenants and occupants in making buildings more green and outlines best practices in how they can interact and set goals;

3. Check lists, which include questions or metrics for understanding the sustainable performance of an existing building and identifying opportunities for the future. (For example, is electricity sub-metered? Does the building have solar panels?)

The toolkit was inspired by the recommendations of the Mayor’s Task Force on Existing Commercial Buildings (PDF), which completed its work and published a report (SPUR was a participant) in 2009. That report found that while San Francisco's green standards for new construction were high, sustainability performance standards and tools were especially needed for existing buildings because they comprise by far the majority of buildings that will be here in the future. Less than 1 percent of the city's buildings are newly constructed each year, which means it would take more than 60 years to “green” even half of San Francisco's building stock through new construction.

The commercial buildings task force proposed a voluntary goal of reducing the energy use in existing commercial buildings 50 percent by 2030, with an average reduction of 2.5 percent per year. The Green Tenant Toolkit is designed to help improve those spaces that are leased and may not be undergoing major renovations in the near future.

SPUR has also examined the challenges of resource efficiency for existing multi-tenant residential buildings, which are responsible for as much of our city's greenhouse gas emissions as commercial buildings. Multi-tenant residential buildings suffer some of the same challenges as multi-tenant office buildings, although leasing terms, capital improvement financing and regulations, among other things, are different.

The Green Tenant Toolkit is intended to evolve based on user feedback, so check it out and provide yours at www.greentenanttoolkit.com.

Explore the Green Tenant Toolkit >>

As someone who works on urban agricultural policy, I'm often asked, "Is city-grown food safe?" The question comes from aspiring urban gardeners and concerned eaters alike. And it seems to stem from both a fear of the known and a fear of the unknown. 

First, the fear of the known: Common urban contaminants include lead, arsenic and other heavy metals leaked into soil from old paint, leaded gasoline, modern car exhaust and industrial land-use. These metals are responsible for a whole host of maladies. Heavy exposure to lead, for example, can harm the nervous system and result in other developmental disabilities, especially in children.

Here in San Francisco, a recent study of garden soils confirmed the presence of residual lead in many parts of the city. Similar studies have taken place or are in the works in Minnesota, Chicago and Indianapolis. They all show considerable evidence of lead in urban soil.

Though we know it's present, we don't know the best way to gauge the risk of this lead-contaminated soil. The San Francisco Department of Public Health recently issued guidelines warning that any garden soil  containing lead at more than 80 parts per million poses a risk to children.Young kids have an unfortunate habit of ingesting and inhaling all sorts of things, so oral or nasal exposure to lead-contaminated soil is a very real potential danger to their health. But the guidance included a side note underscoring just how confused regulatory agencies are about this exposure risk:

Note that US Environmental Protection Agency (EPA) and California Department of Public Health (CDPH) use 400 ppm or greater of lead in bare soil as their definition of a lead in soil hazard and the CalEPA State Water Resources Control Board (SWRCB) uses 200 ppm or greater of lead for their definition of clearance prior to land use development. Neither of those values is based on the prevention of significant health effects to children [as opposed to adults].

Which leads to the fear of the unknown: Neither the EPA nor the San Francisco Department of Public Health can provide clear guidelines regarding the danger of eating food grown in soil with elevated levels of lead. Scientists aren't sure about the uptake of toxins in plants, or how much they can transmit to our stomachs. And there's just as much confusion about the risk of other known toxins besides lead: As the EPA's Brownfield program recently noted, even when we analyze identified pollutants with understood health impacts, we end up with more questions than answers. With so many questions, many people react emotionally to this general fear of the unknown. The thought process goes something like this: "Food grows in dirt. Dirt is dirty. So city dirt must be really dirty." 

But should we be more concerned about city-grown food than rural-grown food? I don't think so. First of all, the same highways full of car exhaust that run through our cities also run through our rural areas. And while rural areas don't have the polluting legacy of urban manufacturing industries, they have industrial toxins of their own. Pesticides — including previously-approved-but-now-banned varieties — are prime examples. Another area of concern is biosolids: We routinely take treated sewage from cities and apply it on agricultural fields throughout the country, bringing with it many of the chemicals, including pharmaceuticals, that we flush down our toilets, sinks and other city drains. How much that affects the food we eat is not clear.

Considering all those factors, perhaps we shouldn't assume that rural soil is always safer: Within both urban and rural areas there are some sites that are clean and some that are heavily polluted. Baltimore is considering requiring urban farmers to test their soil; should rural farmers be required to do likewise? Or perhaps the fear of soil toxins in our food supply is greater than the actual risk. Certainly the risk to children who eat soil is different than the risk their parents face from eating vegetables grown in that same soil. What tests should we use to gauge those dangers? 

Though I don't have the answers to these questions, I'm heartened when someone asks me about the safety of city-grown food because it shows the true promise of urban agriculture. That promise lies not in the potential to feed ourselves wholly from within our cities, but rather in using the small amount that is grown nearby to connect us with our larger food system. We need to ask more questions of our food supply, both urban and rural. We also need to call on our government agencies, universities and others to help us answer these questions. In the meantime, I'll continue eating food grown in the city.

On July 13, the California Coastal Commission unanimously denied a permit application from the City and County of San Francisco for coastal armoring along the Great Highway South of Sloat Boulevard. The application was submitted by the City's Department of Public Works, which is responsible for the protection of city infrastructure, including the Lake Merced Tunnel, a 14-foot diameter sewer pipe under the Great Highway. DPW constructed rock revetments (i.e., linear piles of boulders) on the beach in 1997 and 2010 in response to erosion caused by severe winter storms. The permit would have 1.) retroactively approved the un-permitted 1997 revetment, 2.) made permanent the temporary emergency permit for the 2010 revetment, and 3.) added new armoring, extending revetments and adding tangent pile walls (made from reinforced concrete piles) behind the bluffs.

The surprise ruling, against the recommendation of commission staff, is a significant victory for surfers and environmentalists, who oppose coastal armoring for its impacts on the beach, including the loss of sand and impeded coastal access. After presentations from the DPW staff and project opponents, the commission protested the ad-hoc nature of the city's coastal management and insisted that they would not approve additional armoring until a long-range plan was in place. Members were explicit that they intended to send a message to city officials. The commission did not take up the substance of the city's application, which included an analysis of future risk in three locations, including one where there is an immediate risk of damage.

As the project leader of SPUR's work on Ocean Beach, I provided testimony on the status of the Ocean Beach Master Plan, due out in January. The ruling has significant implications for the plan, which is intended to provide the long-range framework the commission is demanding. By precluding further short-term armoring, the commission has increased pressure on the project to provide an answer, and on the participating agencies to quickly adopt its recommendations. But the short-term picture is left unresolved. The Master Plan is a non-regulatory package of recommendations, which will guide a host of federal, state, and local agencies, each with its own internal planning processes. The recommendations must be translated into distinct and fundable projects and subjected to review under state and federal environmental regulations CEQA, NEPA and the California Coastal Act. All of this will take several years, during which additional storms are likely to occur. Although they did send a clear message in favor of long-range planning, chances are that the commissioners will find themselves facing an emergency armoring permit before they see a long term fix come to fruition.

Read our Urbanist issue on the future of Ocean Beach >>

Read the latest on the Ocean Beach Master Plan >>

How do we know this? By measuring our “ecological footprint,” a measure of natural resource consumption as a function of goods and services purchased. Using natural-resource accounting techniques, the balance of consumption for all countries is precisely measured against the world’s capacity to regenerate those resources. When combined with a mathematical input-output model, calibrated by socioeconomic and demographic data, the analysis can be performed at a wide range of scales: personal, household, factory, company, country, planet.

A few years ago, we invited Oakland-based Global Footprint Network — founded by Mathis Wackernagel, the creator of the environmental footprint concept — to present at a SPUR forum. After the forum, we got to talking about how a San Francisco footprint analysis could broaden the conversation around sustainable urbanism. Global Footprint Network’s staff was interested in bringing its largely international portfolio of footprint analyses closer to home. We put together a research plan and a steering committee, and received seed funding from the Wallace Alexander Gerbode Foundation.

The completed footprint study (PDF download) found that the average San Franciscan’s overall footprint was about 6 percent higher than the average American’s. But our average footprint was lower than you might expect since city dwellers generally have larger footprints (due largely to residents’ higher disposable incomes and greater levels of consumption). As you might guess, the categories where we exceeded U.S. averages were consumption of food, alcoholic beverages, restaurants and hotels, and transportation (the latter largely in moving and freight services, and in air travel).

Our work also revealed some universal principles about footprints as they relate to other geographic variables. Some of our analyses compare U.S. city footprints, including San Francisco’s, to urban density and average income to test how these variables affect sustainability. We found that a $1,000 per capita increase in purchases of goods and services correlates with a 0.09 global hectares per capita increase in footprint, while a 100 people per square mile increase in population density is associated with a 0.06 global hectares per capita decrease in footprint. So as a city becomes denser, we reduce our footprint, but as we become wealthier, we increase it. Is there always a tradeoff between quality of life, as measured by wealth, and the ecological footprint? Not necessarily. The pursuit of freedom, good health, fulfilling lives and a high standard of living — in other words, a high Human Development Index, a measure tracked by the United Nations — can accompany a wide range of footprints:

As this Global Footprint Network chart shows, some countries are doing a better job at this than others (hover your mouse over the moving dots to see the country names). Achieving true sustainable development includes both a high level of human development and a low ecological footprint.

In our study, because of data limitations, we had to aggregate results to the entire San Francisco Metropolitan Statistical Area, and not to the city of San Francisco. This was disappointing because we couldn’t determine the footprint outcome of city sustainability measures such as our high recycling rate, green building requirements, climate action plan and high level of transit ridership. It also limited the study in some areas and introduced error, because we had to use national averages rather than regionally specific production factors. For example, it doesn’t make sense that the San Francisco Metropolitan Statistical Area has an above-U.S.-average footprint for energy, water and other utilities. The majority of the water supplied to San Francisco, the Peninsula and the East Bay is delivered by gravity, and our energy utilities — public and private alike — are among the cleanest in the country. California also has much better energy-efficiency performance than the U.S. as a whole, so you would expect our utility footprint to be lower all around.

Our analysis, which includes suggestions of areas to pursue further, goes about as far as an initial footprint study realistically can. But this analysis could be used as a baseline for more issue-specific work. For example, at SPUR we will be delving into the food sustainability question — by far, the largest component of any U.S. footprint analysis — through the work of our new Food Systems and Urban Agriculture program, which launches next month.

Download the ecological footprint report >>