December 13, 2018
Urban community garden
Expert Q&A

Closing the Green Space Gap in the U.S.

by Jeanine Barone  

Rachel Morello-Frosch, PhD, is a professor in the Department of Environmental Science, Policy and Management and the School of Public Health at UC Berkeley. Her research examines how race and socioeconomic status influence environmental health disparities among U.S. communities; in particular, she focuses on environmental chemicals, climate change, drinking water, and environmental sustainability. We spoke with her about a study she recently published on disparities in access to urban green spaces—which includes parks as well as gardens, playing fields, and areas with tree canopy—among different demographic groups in the U.S., and the impact those disparities could have on residents’ health.

Can you tell us a bit about your study and why the results are noteworthy?

Our study looked at the distribution of green space in relation to neighborhood socio-demographic factors. Two things made this study unique. One is that it was a national study; most studies that look at distribution of green space or at green space and health outcomes tend to focus on a particular state or city or area. This is the first study to takea national look at this. And the other unique thing is that we looked at temporal patterns in terms of changes in greenness or green space within a 10-year period, from 2001 to 2011. This is the first study of its kind that we know of that has done that.

There is a burgeoning literature looking at access to green space and its potentially beneficial health implications. For our study, we used satellite data called the “normalized difference vegetative index,” or NDVI, to look at urban neighborhoods across the country, which we defined by census tracts. We found that those with a higher proportion of residents of color had less green space in our base year of 2001 compared to neighborhoods with higher proportions of white residents. We also saw that neighborhoods with a higher proportion of residents of color were more likely to experience further decreases in greenness between 2001 and 2011 than those with higher proportions of white residents.

This relationship between the racial/ethnic makeup of neighborhoods and green space access persisted even after we took into account other things that might explain the association, including population density, the proportion of renters, the concentration of poverty or affluence, and regional differences in climatic factors like average annual rainfall and temperature. For example, Arizona, which has a lot of desert, is a lot less green than places on the East Coast. When we took those sorts of things into account, the disparity in terms of baseline green space and temporal change in green space still held true.

Does your research take into account how attractive or well-maintained the green space is—whether it’s clean and lush vs. filled with scraggly weeds or maybe even garbage?

That’s a great question. Because we used satellite-derived images of vegetation for our analysis, our study was not able to distinguish whether the green space was, for example, a park or urban agriculture space vs. an abandoned lot. We addressed this limitation of our study in the discussion section by emphasizing that this is an area that needs to be looked at more closely. There is a lot of variability in terms of great green space and not-so-great green space, like abandoned, weedy lots.

Why do you think urban green spaces have decreased in low-income neighborhoods over the years?

This is an important question that our study raises but that we weren’t able to answer directly. It’s possible that declines in green space could be due to increases in development and construction of housing or other types of buildings, as well as the widening or division of roadways. Also, if cities are not investing in the maintenance of existing green space in low-income neighborhoods, the community pressure and incentives may not be there to preserve them. Although we looked at national trends in green space access, it’s important to acknowledge that patterns and specific drivers that affect green space access over time are going tovary by region or metro area. It’s not going to be the same story for every place.

What are the physical and psychological benefits of urban green spaces for adults and kids?

There’s a pretty strong body of literature that shows that exposure to green space and natural areas, including in urban settings, can reduce levels of stress. Green spaces can also potentially increase the social cohesion and connections among residents in neighborhoods—since they provide a place where people are able to hang out and interacttogether outside.

Green space can provide really important opportunities for physical activity, both for kids and adults. We know that communities that have access to opportunities to be outside recreationally and learn about the environment and nature have higher levels of physical activity, which can improve mental health outcomes for kids and adults. In terms of the physical environment, trees and other green space can reduce exposure to noise, which we know can adversely impact health in a variety of ways. Green space, particularly tree canopies, can reduce levels of air pollution on a local scale and can also protect residents from spikes in temperature due to extreme heat events, such as a heat wave.

In addition to these mental and physical health benefits, are there potential economic benefits to improving access to green space?

Yes. The development and maintenance of green space can bring certain kinds of jobs and economic development opportunities. A lot of green space initiatives, particularly in urban communities, entail the development of urban farming initiatives, which can create opportunities for jobs and training in these areas.

One example of these initiatives is in New York City, where there is a community organization called Sustainable South Bronx, based in Hunts Point Riverside Park. They have been working closely with the community to develop a 4-mile stretch of waterfront along the East River, both as a greenway to improve access to park space and promote physical activity, and as a way to promote local job opportunities, since the greenway will require development and maintenance. The waterfront was previously industrial and abandoned.

The term “green gentrification” refers to the trend of building condominiums and housing for the wealthy next to urban green spaces (either existing ones or new green spaces that are created as part of the development). Is this trend perpetuating environmental injustice?

A lot has been written about so-called green gentrification, and I think it’s definitely a legitimate concern, particularly in low-income communities and communities of color that are really feeling the pressures of gentrification more broadly. While there’s not a simple answer as to how to address this, I think one of the key things that needs to be addressed is to make sure that governance of urban green space really involves all residents and doesn’t benefit one set of residents over another.

For example, in Lake Merritt in Oakland, which has been undergoing a lot of gentrification pressure over the last decade, there’s been a lot of discussion about changing the rules of what’s considered acceptable use of the park. There were activities that were considered okay and had been going on a for a long time, like drumming circles; and then new people come into the neighborhood and, all of a sudden, what used to be considered a great drumming circle that people loved on the weekends is now treated by the new residents like a nuisance. So, changing the rules on how parks are accessed and which activities are considered acceptable has to be a community-wide discussion. It can’t just be the new residents coming in and shutting out the long-term residents who’ve been living there a long time.

The other issue is equity of funding across parklands in a city. There are cities that have a lot of green space but the distribution of resources to maintain them is not equitable. For example, some of the parks in low-income communities and communities of color are not as well maintained or the hours are not as long as in other communities, which can severely limit access. The parks commission is where these “struggles of access” play out.

Can you discuss some of the initiatives underway to increase green space in low-income and minority areas?

In the [San Francisco] Bay Area, there are a lot of efforts to push for access to urban green space in low-income communities and communities of color. There are two main avenues through which this is happening: through parks and recreation opportunities—either more parks, or better access and more recreation opportunities within existing parks—and through what we call food justice strategies, like the development of urban farms, which in turn enhances or increases green space. One of my favorite projects is Ubuntu Green in Sacramento. This involves a couple of other organizations, Liberation Permaculture and Sacramento Yard Farmer. It’s a conglomeration of food justice advocates who are trying to promote the development of urban farming and edible home gardens in the city.

In Oakland, the Oakland Climate Action Coalition is trying to push for a city-wide strategy to promote urban agriculture, in partnership with the Oakland Food Policy Council. There’s also been a lot of effort in Oakland to work with the city Parks and Recreation Department. As I mentioned, Oakland is experiencing a lot of gentrification, like other places in the Bay Area. And yet, Oakland has some really important parks with a lot of community history, such as DeFremery Park, which was an epicenter for community organizing—including for the Black Panthers Free Breakfast Program in the late 1960s and early 1970s. We want to make sure that access to those key assets and the preservation and celebration of that community history is not erased by the gentrification of the neighborhood.

In Los Angeles, there’s the Los Angeles Million Tree Initiative, which has played a key role in the city’s tree planting program. This initiativeworks a lot with the LA Conservation Corps to enhance tree planting in Los Angeles because they want to address and fortify neighborhoods to adapt to the inevitable frequency and intensity of extreme weather events. And also because, as I mentioned before, trees can improve air quality on a local scale. Other cities are also involved in million tree initiatives, including Denver and New York City. Another initiative that’s part of the LA Conservation Corps is called Little Green Fingers. It supports the development of community gardens throughout low-income neighborhoods and communities of color. In New York, there’s the Sustainable South Bronx program that I mentioned earlier.

Do we know as yet how these interventions or initiatives impact public health or improve health equity?

I do not know of studies that have looked specifically at the ways in which these specific interventions have improved health outcomes on the local scale. Part of the challenge is that a lot of these initiatives are relatively new. And it’s very hard to parse out when we’re seeing health improvements, to what extent, and how much can we attribute it to the enhancement of green space opportunities in conjunction with other improvements that may be going on in these places at the same time. Very often, when government or communities are coming together and investing in the common good, like green space, chances are that there are other policies being implemented at the same time—because that sort of community has an ethos, if you will, of investing in improving community well-being more generally.So, it’s very hard to quantify the health benefits of one specific local initiative.

How can members of the public get involved with initiatives to support green space?

Often the best way to start is to find out what’s going on in your own neighborhood. Community gardens are an easy thing to get involved in; there also may be local cleanup initiatives that you can learn about through your parks and recreation department. In West Berkeley, where I live, a group has been working fairly regularly to daylight Strawberry Creek, which is a method of preserving and protecting small streams to encourage the proliferation of native plant and wildlife species in that area. There are creek daylighting efforts going on all over the country.

Another way citizens can get involved is to make it clear to their local government that green space, tree canopies, and access to parks are important to them, in addition to the regular things that government should be taking care of, such as sewage systems and potholes and roads. Communities and neighborhoods can mobilize and let their representatives know that they want to see more tree planting in their area or other investments to cultivate green space and provide more recreational opportunities for kids and adults. Individuals and communities can push for funding to improve or redo playing fields for kids, and to make sure that children have access to those fields on the weekends.

Bottom line: Be engaged and let your representatives know that these things matter to you—that they’re on par with any of the other services you expect from local government, not an afterthought.

Also see our earlier interview with Dr. Morello-Frosch on endocrine-disrupting chemicals.