Constructed Climates

Trees and natural vegetation provide the right environment for positive social interactions, calm domestic stresses, and enhance child development. Wealthy residents can afford the choice to live in treed or untreed neighborhoods, and correlations of vegetation and income bear evidence of the most commonly preferred choice. In those places, citizens rally against developments with impervious surface and call for public funding of natural open space. Seemingly, these are not the citizens with the greatest need for the social benefits from publicly funded trees.

Low-income citizens live with less vegetation, perhaps without affordable options. In the places where they live, additional natural areas might serve as social gathering points for positive social opportunities and might reduce crime rates through enhanced community vigilance.

Perhaps the most important and lasting benefit of vegetation involves better developed children with a higher sense of delayed gratification. The ability to sacrifice short-term pleasures for long-term benefits has implications for every aspect of life: The important lessons behind planting a seed in April and harvesting food in July can’t take place in parking lots. I suspect similar lessons are learned each spring, perhaps passively, from watching perennials resprout and trees leaf out. If a child’s bedroom window shows only roads, parking lots, and strip malls, growing children lose this natural education. Social justice demands promoting urban open spaces, and every child should have the view of a tree outside his or her bedroom window.

Admittedly, the evidence for these positive social aspects for vegetation remains scant, and much of what evidence exists arose from studies of distressed social conditions. We need more studies across a range of socioeconomic levels pursuing the human social benefits of urban open space.

What’s the dollar value of enhancing the natural environment of these children growing up in poverty? I use Durham County as an example, where the U.S. Census reports about 40,000 Durham citizens in poverty, with about 10,000 of them under 18 years of age. Suppose we could hope for a 5% gain in childhood development due to enhanced vegetation and trees, a gain on the high side of the studies performed at the Chicago public housing developments. That number fully admits that 95% of a child’s development comes from more proximate causes, unrelated to backyard nature. Natural areas provide a benefit, but a small one compared to parents, friends, and teachers. Also suppose, rather pessimistically but erring on the side of underestimation, that these children become adults who live in poverty, earning about $10,000 per year. If growing up in a more natural environment resulted in a 5% “better” development, say through enhanced ability to delay gratification, and if that enhancement resulted in a 5% gain in income, then each of these citizens would earn an additional $500 each year. A small gain, yes, and perhaps realized by just a few children planting seeds for the future, lifting themselves out of poverty. Considering all of Durham’s 30,000 adults who live in poverty, that increased productivity could yield an additional total income of $15 million per year to this population. Even assuming that enhanced vegetation yields only a 1% gain in childhood development, the dollar benefit might still reach $3 million per year. Certainly these numbers justify a significant program enhancing vegetation where poor people live that would pay for itself through better lives. Enhancing urban natural areas today for better, higher-earning citizens tomorrow truly represents a city’s delayed gratification, and that enhancement resulted in a 5% gain in income, then each of these citizens would earn an additional $500 each year. A small gain, yes, and perhaps realized by just a few children planting seeds for the future, lifting themselves out of poverty. Considering all of Durham’s 30,000 adults in poverty, that increased productivity could yield an additional total income of $15 million per year to this population. Even assuming that enhanced vegetation yields only a 1% gain in childhood development, the dollar benefit might still reach $3 million per year. Certainly these numbers justify a significant program enhancing vegetation where poor people live that would pay for itself through better lives. Enhancing urban natural areas today for better, higher-earning citizens tomorrow truly represents a city’s delayed gratification.