Despite lingering unease, some sense of normalcy has taken hold in Orange County as residents vaccinate, masks come off, and the economy peeks its head out from more than a year of the Coronavirus public health crisis. 

Yet local officials, activists, and public health experts warn the next looming threat — potentially as deadly — lies in wait. 

In central and north Orange County, the concern is that residents living in highly-developed and built-out cities like Santa Ana, Garden Grove and Anaheim are already in the midst of a brewing climate crisis, one where resulting climbing temperatures and increasingly intolerable heat make their homes uninhabitable.

Consider that the area faces steep open green space and tree shade shortages, and is increasingly dominated by concrete heat islands that raise temperatures even throughout the night. 

Add to that, poor air quality along with large numbers of homeless, elderly and poor residents with insufficient air conditioning, and experts say you have the county’s next public health crisis.

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That was the warning that climate change activist Jose Trinidad Castaneda gave to City Council members in Santa Ana — one of central county’s most densely-populated areas — at a meeting in early May. 

“It’s an existential threat,” Castaneda, a Fullerton resident, told council members during public comment. “The summer has begun, temperatures will continue to rise … so what will you do?”

Given that kind of rise in heat, Dr. Clayton Chau, the county’s Public Health Officer, also looks to the possibility of heightened threats by mosquitos and vector organisms that spread infectious diseases: 

“As science has demonstrated, there is a strong correlation between climate change and infectious diseases where viral vectors (like mosquitos) mostly jump hosts, causing diseases in humans, (such as) H1N1, Zika and most recently Coronavirus.”

Dr. Clayton Chau, the county’s Public Health Officer, in a written response to questions on July 1

Dr. Kathleen Treseder, a biology professor at the University of California, Irvine, warns that the effects of the climate crisis won’t be the same across the county.

Treseder sees a situation where coastal residents experience impacts quite differently than inland residents. 

She also notes that inland communities like Santa Ana, and those even further inland like Riverside and San Bernardino, are much more impacted by poor air quality.

Naturally occurring coastal breezes push harmful emissions and particles from west to east, she said, causing a disproportionate level of air pollution for inland communities.

“In places like Laguna Beach, we don’t necessarily walk around in smog,” Treseder told members of the Laguna Beach Democratic Club, at a meeting on June 2. “These things do not respect city boundaries. They move all over.”

Air quality is also known to get worse when temperatures rise through events like heat waves.

A community pool located on the westside of Santa Ana. Credit: JULIE LEOPO, Voice of OC

Treseder even postulated that higher rates of mortality in Santa Ana during the Coronavirus pandemic could be due to the fact that residents already tended to suffer more from respiratory issues as a result of poor air quality. 

Flor Barajas-Tena, a Santa Ana resident and open space and parks advocate, raised that alarm bell last year. In a Voice of OC op-ed, she cited the California Environmental Screen, a science-based mapping tool that identifies California communities most affected by pollution.

The map showed that census tracts spanning Santa Ana’s west side Santa Anita neighborhood and Garden Grove’s Buena Clinton neighborhood had high concentrations of harmful air particulates and a high percentage of asthma-related emergency room visits.

Those neighborhoods also surround 102-acres of open green space currently known as the Willowick Golf Course, which the City of Garden Grove has moved to sell in a manner that critics have called out as non-transparent — with potentially adverse impacts to the surrounding neighborhood. 


Castaneda at the May 4 Santa Ana meeting wondered aloud what may happen to those most vulnerable to the crisis, who don’t have access or can’t afford sufficient air conditioning:

“We will have situations where people experiencing homelessness, people living in mobile home parks, and people in apartments with no air conditioning units will have greater challenges dealing with extreme heat waves and heat risk than others.”

When the City of Santa Ana opened up its hotline for utility bill assistance — among other services — for residents struggling financially during the pandemic, officials reported receiving 2,580 calls between August and October of last year, according to city data.

Santa Ana City Hall reported receiving 2,868 formal applications for utility bill assistance around that same time, and granted a little more than half of those requests — a total $896,000 in assistance to residents.

Irvine resident and climate action organizer Ayn Craciun, in turn, points to a statewide utility bill debt problem: “There are a huge number of people who are behind on their bills already in California. We are looking at a situation where people don’t have equal access to air conditioning.”

“On top of that, we have factors in the built environment such as extreme heat and a lack of shade trees, which can bring down temperatures in a built-out city and come with a variety of other advantages,” she added. 

Shade trees can also sequester carbon and reduce a given area’s level of air pollution, which in turn could have beneficial impacts to people’s respiratory health.

There is data from the U.S. Forest Service that specifically examines tree canopy coverage in different U.S. Census tracts and compares it to other factors like socioeconomic status, air quality, and frequency of asthma-related hospital visits.

In one census tract spanning some parts of Santa Ana’s Madison Park neighborhood, 80% of the more than 5,674 people living there as of 2010 lived below two times the federal poverty level, while the tract has a 17% tree canopy cover in proportion to its total area.

In that same tract, the percentage of asthma-related emergency room visits per 10,000 people was 53% between 2011 and 2013.

In a census tract spanning El Salvador Park and parts of the Artesia Pilar neighborhood, 88% of the 5,822 people living there lived below two times the federal poverty level, while the area has a 24% tree canopy cover, according to the data. 

In that tract, the percentage of asthma-related emergency room visits per 10,000 people was 40% between 2011 and 2013.

Pedro, a Santa Ana grocery truck owner, makes one of his stops in Artesia Pilar neighborhood in Santa Ana. Credit: JULIE LEOPO, Voice of OC

Questions over public health preparedness and response linger on the county level — specifically over the county Health Care Agency overseeing public health, where Dr. Chau is also in charge.

Just last month, a scathing Orange County Grand Jury report found the County of Orange was unprepared for the Coronavirus pandemic due to poor planning and public messaging when the pandemic showed up, and unfilled jobs in the Health Care Agency.

Among their official recommendations to rectify these issues in the event of another crisis, grand jurors suggested the county close funding gaps in disaster and hospital response plans.

Chau on Thursday wouldn’t give specifics on how the Health Care Agency would respond to the grand jury report, only saying that a new statement around the agency’s “vision, mission and goals” would come “soon.” 

Castaneda at the May 4 Santa Ana meeting wondered aloud what may happen to elderly and homeless people in the city who pass out from heat exhaustion, especially in areas where people may not find them.

At one point, during public comment, he stopped himself: 

“I just don’t even want to think about it.”

Brandon Pho is a Voice of OC staff writer and corps member at Report for America, a GroundTruth initiative. Contact him at or on Twitter @photherecord.

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