Americas Environment & Climate

Longer life expectancy and improve life seen projected with more trees and expanded green space

By Cesar Antonio Nucum Jr.

LOS ANGELES – The proverbial belittling of the otherwise important functions of abundant grown trees and ampler and better green space as beautification strategies can now be regarded a thing of the past as it is now known that tree canopy and park space directly affect our health and our survival on Earth.


This comes as new research and the realities of climate change have led to a push for more and better green space and efforts to address inequities in access to parks and shade just as freeways and palm trees have historically defined Los Angeles as the second-largest city in the United States.


Research by UCLA’s Fielding School of Public Health found that increasing tree canopy and park access, particularly in green-poor areas, could add nearly a million years of life expectancy across Los Angeles County and dramatically improve life for low-income residents of color.


In a national briefing of the Ethnic Media Services recently, panelists explored Los Angeles as a case study in the importance of urban greening, explain the link between green space and human health, and map out what it will take to implement changes that benefit the whole city as an example for other cities across the country.


At the panel were Michael Jerrett, Professor, UCLA Department of Environmental Health Sciences and Co-Director, Center for Healthy Climate Solutions, Fielding School of Public Health, Rachel Malarich, City Forester for the City of Los Angeles, Marcos Trinidad, Senior Director of Forestry, TreePeople, Bz Zhang, Project Manager, Los Angeles Neighborhood Land Trust, and Jon Christensen, Adjunct Assistant Professor, UCLA Institute of the Environment, Luskin Center for Innovation, and Laboratory for Environmental Narrative Strategies.


Jerret mentioned that the more parks and trees there are in a given neighborhood, the higher the area’s life expectancy referring to a July 2023 UCLA study he co-authored, which found that bringing green space in LA County to median levels could add up to 908,800 years of collective life expectancy to residents in under-resourced communities.


“While the study found that life expectancy in wealthy and verdant Beverly Hills was 90, the median in south LA communities less than 15 miles away was 77. The total expectancy ranged countywide from 68 years in poorer south-central areas to 93 in affluent places like Malibu,” revealed Jerrett.


Jerrett clarified that in already “very leafy areas, like Brentwood, or parts of West LA, there’s not a lot of impact in adding more green space,” but in disproportionately less green areas in the east, south and far north — where two-third of LA County’s Black and Latino population resides — merely expanding parks to county medians would add 164,700 years of life expectancy to the region, with Black and Latino residents receiving 72%, or 118,000 of these years.


Malarich added that the health benefits that come from more parks and trees depend on more than just planting.


“In order to achieve those benefits, we need to have healthy trees regularly maintained to live their own full lifespan in the neighborhoods which most need them,” Malarich stressed. “The city’s Urban Forest Management Plan has four pillars: planting new trees, maintaining existing trees, preserving these trees amid new construction and development, and engaging the communities who live with these trees.”


“When we talk to community members, there is often frustration because the trees haven’t been maintained,” Malarich explained. “The industry standard is to inspect trees and trim them as needed every five to seven years; the city’s current cycle is closer to 18 years.”


Trinidad, for his part, reminded that the most sustainable urban forests are planted and supported by members of their own communities.


“Now in its 50th year, the urban greening nonprofit TreePeople has been shifting from an all-volunteer model of planting, maintenance and community education to a hybrid model which includes “workforce development,” particularly training youth interested in environmental careers to work with community organizations to green “neighborhoods which need trees the most,” like northeast and southeast LA,” Trinidad explained.


Though TreePeople is based in LA County, Trinidad continued, “its model of community investment in what is needed to have sustainable, sustainable urban forests — namely planting, maintenance, preservation and education — is meant to be shared well beyond LA  … and want to share our process with the rest of the world.”


Zhang taught that to invest in more green space for underserved communities means investing in those communities as caretakers of this space.


The Los Angeles Neighborhood Land Trust (LANLT) that Zhang managed has created about 30 parks and gardens across 21 acres of green space for over half a million LA County residents since its inception in 2002.


Christensen, on the other hand, believes that the access to urban greenery is ever-more crucial as humankind becomes an increasingly urban species

“As of 2007, over half of us live in cities, and that’s expected to go up to 70% by 2050. Cities are our habitat and our resilience to climate change — the resilience of our own health as a species — requires that we invest in cities, which means remedying the inequities which have shaped our urban environment. It’s a matter of life and death,” Christensen reminded.


“Los Angeles is a model of global concern for understanding urban ecosystems and, in California alone,  $100 billion dollars will be spent on green infrastructure, urban greening and climate resilience over the next several years — half of it from the federal government and half from the state,” disclosed Christensen. “As governments worldwide begin to implement similar measures, “We need to recognize that planting trees is not enough; we need to ensure that the communities which most need them can thrive with them.”