When Andy Lipkis was growing up in Baldwin Hills in the 1950s and ’60s, the air was so thick with smog, just breathing caused him pain. The pollution was even damaging the trees at his summer camp in the San Bernardinos. So at 15, Lipkis set out to replant patches of forest with smog-resistant trees. By 18, he had launched the nonprofit that would become TreePeople, planting seedlings at camps throughout the mountains. But his pursuits have been far more than arboreal. Lipkis was there at the founding of the L.A. Conservation Corps, which provides jobs and training to kids from underserved communities. He helped the city’s recycling program get off the ground by appealing to schoolchildren to teach their parents about it. Headquartered in a sylvan 45-acre park at the hilltop intersection of Mulholland Drive and Coldwater Canyon, Lipkis’s organization has put close to 2 million trees in L.A. soil through its public outreach efforts, but you won’t hear him say it’s because of an abiding fondness for saplings. “I have shunned ‘tree hugger’ my whole life because I didn’t want to be dismissed,” Lipkis says on a recent morning as schoolkids tuck seeds into planting trays at the TreePeople Center for Community Forestry.
Bearded and self-effacing, the 60-year-old UCLA dropout wants to discuss trees, sure, but also his vision for transforming L.A. into a vast watershed that harnesses the storm water that would normally wash out to sea. Case in point: On Elmer Avenue in the northeast San Fernando Valley, a multi-agency effort that Lipkis participated in retrofitted homes with climate-appropriate gardens and permeable concrete along with rain barrels. Parkway strips were remade into creeklike gullies to filter water before it goes into underground chambers and percolates into the local aquifer. Along with mitigating floods, the tweaks are estimated to have replenished the groundwater basin with 13 million gallons. For Lipkis, a green street like that is just the beginning of what the future could hold.
You’ve said that about 23 percent of the city is beneath a tree canopy. You want more, though. Why?
When you look at a map of canopy density, the lowest tree canopy—under 7 percent—is in South L.A., East L.A., the northeast San Fernando Valley, and the harbor. If you look at the maps of chronic disease—lung disease, asthma, morbid obesity, and diabetes—in urban areas, they map out inversely to density of tree canopy. Now that’s a socioeconomic map. But there’s this well-documented notion of cumulative impacts: The more stressors you have, the more vulnerable people are to being pushed over into chronic diseases. So it’s important to protect people by increasing the tree canopy to reduce heat stress and sound stress and to sweeten life some. There’s lots of good research about how people who have views of trees recover faster from surgery and with less pain medication; there’s crime research showing that in Chicago communities, there is a change in crime statistics with greater tree canopy.
TreePeople helps neighborhoods conduct plantings, but you no longer go in, marshal the troops, and do the job yourself anymore. What prompted the change?
You know, trees seem like a pretty wimpy technology to lean on if they’re not going to live, and they won’t live unless people engage. So we train people who say, “My community has a dream, and we want it to look different.” We require them to get neighbors together to build that shared dream. If they need 100 volunteers to get the job done but have only 20, we’ll give them the other 80. We’ll support them with the infrastructure. We’ll help them get their permits. But we learned through the pain of not seeing the highest success that if they don’t do it, their project will fail.
So it’s not just about plunking a tree in the ground and hoping it will sprout?
Trees are like acupuncture needles. They actually can heal community issues, solve problems physically and socially, but you have to think of them in that way, strategically, with the right tree going in the right place. That may mean fruit trees in certain areas or shade trees to protect lives; it may be that trees are planted to treat polluted water, which they do, or to increase soil moisture or prevent floods, but which tree you use and where you put it is critical.
I thought trees just fall over in floods. How do they help prevent them?
Look at the oak tree, our great native son. For me, it’s the multitasking superhero of our ecosystem. From the first acorn that sprouts, it starts to transform its world and the world around it. As it’s grown, it has built a sponge, dropping leaves and twigs. It attracts more and more species to break down the soil. Any of our oaks are said to host at least 300 species of critters in the canopy and the soil. If you can imagine microscopic critters all the way up to snakes and rodents digging and drilling, the soil looks like a sponge; it’s totally porous.
Why is porous soil significant?
Take an oak with a 100-foot canopy. A flash flood created by a 12-inch rainfall that hits that spot would generate 58,000 gallons of water; the tree handles all that, but the capacity of that sponge is actually 123,000 gallons—cleaned and going to the aquifer. That’s substantial in terms of flood protection, water supply, cooling, being a pollinator habitat. They’re a great fire barrier, too. The fire department says, if you have a line of oaks, a brushfire can’t get through. And they grow back. So think about what happens when you take the tree away: The next time there’s a flood, it’s going to go down the stream, and someone’s likely to get hurt. You lose your soil. You set up this cascade of unsustainability, which defines our challenge.
The challenge—climate change—is why you led a delegation to Melbourne last fall.
Climate scientists basically said that Australia is going to be one of the first areas to experience what I’m calling early-onset extreme-climate impacts before sea level rise—the radical swings, with hotter hots, wetter wets, colder colds. And sure enough, there was a 12-year drought. But it also came with severe heat near the end, temperatures that exceeded 115 degrees in every one of their major cities. People started dying.
What’s one thing about their response that impressed you?
They’ve done intense public health research on what they need to do to protect people, and the conclusion was that if you want to survive severe heat, you want a dense tree canopy—not just for shade but to create a natural evaporative cooling machine. So they’re creating urban cooling centers with trees. One of them is the Melbourne Cricket Ground. It’s a 100,000-seat stadium in their downtown with a big park, and they’ve retrofitted the space with thousands of trees and the life support for them. They’re not using their water supply; they’re using all the toilets from the stadium. Plus they’ve tapped a sewer main and put a treatment plant underground that treats all the water.
Do you think L.A. has the wherewithal to do anything that enterprising on a mass scale?
Yeah, I do. That has been the core of my work for the last 20 years, to show it’s technically feasible, economically feasible.
But the city is notorious for having overlapping agencies and a lot of red tape.
Yeah. We tried for years to get different agencies and departments to listen, and they wouldn’t. So I raised a million-and-a-half dollars to do this six-year research project. We had 200 agencies, scientists, and economists do a massive cost-benefit analysis that was put into a modeling tool to show how separate agencies could combine resources to invest in green infrastructure. And it blew their minds. We spend billions every year, but it’s all atomized into these separate infrastructure systems. Kind of like when you take the tree out—what are we using to replace the services that the tree provided? Different infrastructure agencies. And they all spend, just not collectively; they’re all in their own silos. My work is to show them that if they would cooperate, it would work. You know sustainable solutions are never the ones chosen because they’re the ones that are most expensive.
The drought is killing trees. In fact, because of drought and beetles, the San Bernardino forest is in the same state it was in when you were a young man.
If not worse.
You see trees dropping branches during heat waves. A previously unidentified beetle has turned up in trees at the Huntington Library in San Marino. There’s—
Sudden oak death syndrome. It is scary times. I’m not in denial. We’re in new territory across the world. The challenges are greater and more scary than we’ve ever seen. But there’s some amazing plant-related climate science going on right now in several institutions. And we’re going to pull in the best science we can to try to get these prescriptions.
Back to the drought. Trees draw in a lot of water. Jet Propulsion Lab climatologist William Patzert has gone so far as to say that his own community, Sierra Madre, is so water depleted that it should reduce the number of trees.
He’s not wrong about the notion of too many straws. Start with the right tree in the right place. There are oaks and other trees that tend to go dormant in the summer, so they’re not pulling water all the time. The role they play in rebuilding groundwater is absolutely essential. We have to do that. We have a lot of water; we throw most of it away.
In terms of rainfall washing into storm drains and out to sea?
When it rains an inch in L.A., according to the city, 7.6 billion gallons might fall, and half—3.8 billion—runs off. None of that recharges the aquifer, and we’ve been overdrafting. We have to fix that. We have to be recharging the aquifer. And we can.
Climate change is supposed to be unrelated to the current drought, and while global warming is reducing the snowpack, it won’t necessarily reduce rainfall.
That’s part of it. The other is the climate science around Los Angeles indicates that precipitation is going to go up slightly, with fewer but more powerful storms.
So more flooding.
We know how quickly things can change from drought to flood. It happened in Australia, and it is happening in Texas right now. This city is incredibly vulnerable. Our flood protection infrastructure is way overtaxed by the expected storm events. We’re going to have to adapt. The question is, Are we going to wait for a disaster or are we going to start making the adaptation? What do we need for the water supply? Extraordinary amounts of money. For water quality? Extraordinary amounts. The only way we get through sensible design is through integration. It saves money and saves neighborhoods.
The Sun Valley Watershed Multi-Benefit Project kind of does that. TreePeople was involved in making it happen. Without getting too technical, how does it work?
Under Sun Valley Park there’s a 2 million-gallon infiltration system that looks like a parking garage; it’s a big tank with gravel on the bottom that captures floodwater and sends it to the aquifer. The county paid to build it, while the city maintains and operates it. Next door is a massive gravel pit that is going to be a beautiful lake, catching floodwater, too. And then we’ll have a huge treatment wetland, and the water will be sent across the street to Sun Valley Park’s infiltration system because the capacity is so much greater than they thought.
This concept is hugely important, but do you ever worry it’s too wonky for people to really get behind?
TreePeople’s core DNA is, This doesn’t work without people engaging. It’s not going to work if people sit back and wonder how we’re going to do it. Our job is to have people see and understand that together we can make it.