The Ficus microcarpa trees along Hollywood’s Cherokee Avenue create a majestic arch. Walking beneath them is an almost otherworldly experience. In the impenetrable shade, as birds chirp high in the deep green canopy above, the air is unmistakably cooler.

Trees are critical for cooling down warming cities like Los Angeles, where temperatures are expected to increase an average of 4 to 5 degrees Fahrenheit by 2050.

The shade that trees produce can cool surfaces like soil and pavement. But trees can also lower the surrounding daytime summer air temperature up to 10 degrees, thanks to water evaporating from their leaves.

That’s why preserving mature trees that form a canopy should be LA’s priority, says Glynn Hulley, a scientist in the carbon cycle and ecosystems group at NASA’s Jet Propulsion Laboratory.

“It’s a pretty precious resource in cities, and you don’t want to take them down—you want to be adding to them,” he says.

Instead, since 2000, many neighborhoods in the LA region have seen a tree canopy reduction of 14 to 55 percent, according to a University of Southern California study published in 2017.

In recent years, the city’s street trees have taken a hit. According to permits filed with the city of Los Angeles’s street services bureau, 263 street trees—including the 18 on the 1200 block of North Cherokee—are slated to be ripped out in the first five months of this year alone for sidewalk repairs and street widening.

Those numbers are for removals of three or more trees at a time and do not include instances where one or two trees are removed for repairs, which do not require a public hearing. They also do not include permits by developers to remove one or two street trees.

“People should be climbing into these trees to stop them from being cut down,” says Hulley.

Hulley is publishing a major study this summer looking at heatwave trends in the region, which he recently presented to a Los Angeles County sustainability task force.

The many devastating—and deadly—effects of heatwaves include increased wildfire risk.

“Heatwaves are not only increasing in frequency and intensity, but also their seasonality is changing, with more heatwaves earlier and later in the year,” says Hulley. “Trees are the most cost-effective way to cool down the urban environment.”

Since 2010, the region has experienced extreme drought conditions, which not only kills trees but also makes them more susceptible to disease. But the drought is only partly to blame for LA’s recent tree loss.

After an era that saw maintenance efforts plummet and budget cuts that restructured the city’s urban forestry efforts, in recent years, more healthy trees have been removed to make way for construction or sidewalk repairs.

Sidewalk repair is important—as is building new multi-family structures to address the housing crisis—but these improvements can be made without losing tree canopy by employing alternative pavement materials, like recycled mixed plastic materials, or changing the sidewalk design to accommodate a mature tree, known as a meander.

Now, experts say a new program approved last month by the Los Angeles City Council to allow developers and homeowners to pay fees to tear out street trees—instead of replacing them at the city’s required 2 to 1 ratio—will exacerbate the problem.

The fee was proposed in response to patterns city officials saw in applications for tree removal permits, according to Heather Reppening, vice president of the board of public works.

For larger construction projects—which already have separate tree-planting requirements per unit dictated by the planning department—developers were filing tree removal permits because they claimed they didn’t have room to plant trees onsite, says Reppening.

Plus, replacement trees purchased by developers often sat unplanted in the city’s nursery, where they can become root bound and die. Repenning says the in-lieu fee money goes into a fund the city can tap to plant trees to maximize their chance of survival.

“The tree removals are necessary,” says Repenning. “But they are sad. You are losing mature canopy. But our urban foresters will tell us there’s value in having younger trees in that it’s actually healthy to have trees of all different ages.”

The fee structure ranges based on the size of the project, not the size or maturity of the removed tree. Developers of large projects can pay $2,612 to remove or forego planting a tree, and homeowners and developers of smaller projects pay $267.

Those fees are far too low, says Travis Longcore of USC’s Spatial Sciences Institute; he co-authored the 2017 study that used aerial imagery to track the deforestation of LA.

That study found that deforestation was most accelerated in neighborhoods popular for McMansionization, where a smaller, older single-family home is replaced by a newer, much larger single-family home.

Longcore is particularly concerned with the $267 fee. He says the fee is low enough that homeowners and small-lot developers will simply pay instead of making a consideration to keep the tree.

“So you remove a tree—which provides a much greater annual economic value to the public—and then you don’t replace it?” he says. “We are incentivizing people to remove them instead of working around them.”

Deforestation was most accelerated in neighborhoods popular for McMansionization, where a smaller, older single-family home is replaced by a newer, much larger single-family home.

Repenning says the low fee, which is equivalent to the cost of purchasing and planting a new tree, will help remove a barrier for homeowners to repair their own sidewalks. The city is relying on some homeowners to front the cost of fixing buckling sidewalks to meet its sidewalk repair program goals.

But the city’s push to repair sidewalks has accelerated the loss of hundreds of mature trees, according to Julie Stromberg, a lawyer who serves on the city’s community forest advisory committee.

“I’m receiving all the notifications for tree removals, and sometimes there is not that much effort from local residents to save them,” she says. “In those instances, there’s no one in the community who is fighting for these trees.”

Stromberg also says she’s seeing trees aggressively removed from places where the city has been sued for trips and falls.

A notice that the 18 ficus trees on Cherokee Avenue would be removed was issued the same day the City Council voted to pay $3 million to a woman who fell and hit her head on a “defected” sidewalk there.

A major class action lawsuit, which was filed on behalf of Angelenos with disabilities, was also the impetus for the city’s sidewalk repair program.

Under both the sidewalk repair program and the in-lieu fee program, streets that see a lot of development or major sidewalk repairs are the most likely to lose tree cover.

While both programs aim to put replacement trees as close as possible to where removed trees had been, there is no guarantee for when and where replacement trees will be planted.

That’s unacceptable for underserved communities that never had much of a tree canopy in the first place, and where trees are helping to clean air polluted by freeways and industry. There is mounting evidence that shows the connection between chronic health problems and tree loss.

“Established and mature trees assist in mitigating the environmental impact as the city of Los Angeles moves away from fossil fuels,” says Jason Gallegos, the planning and land use committee chair for the Boyle Heights Neighborhood Council. “The loss of trees from our community, even a temporary one, adds to a cumulative effect of lung issues, such as asthma.”

There are thriving urban forests just outside the city of LA’s borders that could serve as examples for how officials could work harder to protect existing trees and be more proactive in planting new ones.

Santa Monica is facing a lot of the same challenges when it comes to trees and development, says Matthew Wells, the city’s urban forester. But he estimates that the city loses very few trees through removal—“only a handful per year.”

In Santa Monica, removing a mature street tree requires a developer or homeowner to make a case to the city’s urban forest task force. Often a plan is made to save the existing trees, per the city’s detailed developer guidelines, and paying a fee is seen as a last resort, says Wells.

“We don’t want to stop development—we know we need more housing and more high-quality facilities,” he says. “But if we don’t value trees and we don’t try to preserve them, the design process happens so quickly that if developers are not aware the tree has to stay, they don’t think about it.”

Even notoriously gnarly ficuses are not nuisances if they are well-maintained with proper root pruning, says Wells, who has expanded treewells and widened parkways in efforts to save them.

To quantify the importance of large trees, Wells undertook a tree inventory for Santa Monica, and has has been able to produce data showing the value of its mature trees, some of which have public benefits—including energy and water savings—that are the equivalent of $10,000 to $20,000.

“We need to become a trees-first city, above all else, otherwise we are going to fry.”

Right now, Los Angeles doesn't have enough information to assess the value of its trees—or know how many need to be replaced.

A 2015 report on the state of trees commissioned as part of the city’s sustainability plan—the most recent report made available—noted that the city has 700,000 street trees and 100,000 vacant tree wells, but these numbers are based on 1996 data.

This year’s budget has money for the city of Los Angeles to mount a comprehensive tree inventory for streets and parks, according to Repenning.

The influx of money will also allow LA to hire a citywide tree policy coordinator who will oversee tasks that have been spread across several departments. It may also add up to 40 tree care jobs, including two new positions for preserving mature trees in place during sidewalk reconstruction projects.

Los Angeles is also the beginning stages of putting together an urban forest management plan to help guide the planting, care, and protection of the city’s trees.

That plan could make specific recommendations that address trees’ cooling benefits, says Bryn Lindblad, associate director at Climate Resolve. She recommends adding biochar, an agricultural waste byproduct, to roots to retain water and nutrients.

“The healthier the trees, the more effective they are at converting solar energy into new plant growth through the process of photosynthesis, which helps to cool down our intense urban heat island archipelago,” she says.

Hulley argues that the city could also be more strategic about where trees are planted by adding more in places where their cooling effects will be most impactful. Planting trees on the western side of LA buildings is known to shade structures from afternoon heat gain.

Protecting all healthy trees with a certain trunk diameter could be one solution to ensure that more mature trees don’t get removed, suggests Wells. For now, the city of Los Angeles only protects four native species.

Above all, a city with such lofty climate goals should view trees not just as an environmental priority, but as a crucial public health investment. Longcore points out that trees should be treated as an essential part of the street—much like the city’s similarly sized network of street lamps, which have a dedicated installation, maintenance, and replacement budget.

Mayor Eric Garcetti—who has set a goal of preventing Los Angeles from warming 3 degrees—has garnered attention for a “cool streets” program that paints streets gray. That effort may receive as much as $2 million in funding this year.

The city should be looking at similarly creative, well-funded ways to make room for more trees, block-by-block, says Isabelle Duvivier, an architect and member of the city’s community forest advisory committee.

She has been tracking tree loss in City Council district 11, where she lives, and says at least 199 trees have been permitted for removal since January 2017. That includes 26 ficus and bottle brush trees on South Sepulveda Boulevard and South Naylor Avenue that a local nonprofit have elected to cut down as part of a streetscape improvement project to remove “unsafe, overgrown trees.”

“Trees should not be optional to the homeowner’s whim, but need to be part of the required city infrastructure,” says Duvivier. “We need to become a trees-first city, above all else, otherwise we are going to fry.”