It’s springtime in Los Angeles. It’s unseasonably warm. And one thing is already certain: Summer in this city is going to be a scorcher. The bad news? The city of Angels is designed to retain heat. The good news? There might be a way to begin to begin to chill out America’s largest and hottest city.
Like all large urban areas, LA experiences something called “the heat island effect” whereby the sun’s radiation is absorbed by rooftops, cement, and asphalt, literally baking the city. Pulling data from NASA’s TRM Satellite, the California EPA has estimated for each 1 million people that a city holds, its temperature increases by about 1-degree Fahrenheit. While the city of Los Angeles only has around 4 million inhabitants, the greater LA area actually holds closer to 19 million residents. That means the in-city temperature will likely be around 19 degrees hotter than surrounding natural areas this summer.
But it could be even hotter. That’s because the extra heat initiates a feedback loop in which more electricity is used, and more fossil fuel is burned in cars, (to run air conditioners), which contributes to more greenhouse gases and smog, which, in turn contributes to yet more heat.
So, what’s an ever-expanding, frying-pan-megalopolis like LA to do? The simple answer is to use the tools of nature to provide large-scale and cost-effective air conditioning.
Here’s how it works: In a forested or planted area, green leafy plants absorb the sun’s radiation and use it for photosynthesis. Photosynthesis initiates a secondary process called transpiration. In transpiration, water that is locked in soil is moved up through the roots of plants and “mists” out through their leaves. This creates a “swamp cooler” effect wherein micro-droplets of water from plants cool the surrounding air.
Given that cement equals more heat, but plants bring down the temperature, planting drought-tolerant, native species of trees, grasses, shrubs along with creating community gardens, installing rooftop gardens, making “green roofs,” and using compost (which “jumpstarts” the microbial life in the soil) are all prudent steps to reducing LA’s heat island effect.
Here’s a simple to-do list for homeowners, city planners, and everyone involved in community development:
- Lawns are not necessarily evil. But lawns of one type of grass (monocrops) are not very heat resilient. Plant many different drought-tolerant species together and add clover to lawn seed mixes. Add worms and mycorrhizal fungi (both available online.) Once roots are established, allow lawns to grow to at least 3 inches before cutting. Water less, if any at all.
- Outlaw the spraying of toxic chemical herbicide sprays (especially glyphosate-based “Roundup” brand weed killer). These harsh sprays kill the very microbes in the soil which store water and deliver nutrients to plants.
- Create neighborhood-wide and eventually city-wide compost programs. (see LAcompost.org)
- Make sure all bare soil is covered with mulch, grass, or other plants. Bare soil bakes just like cement.
- Become a soil protector and join the movement to save our soils. (see KisstheGround.org)
By working together and using practices that “regenerate” the soil (known collectively as “regenerative agriculture”) we can cool our city and bring valuable ecosystems back. This will also help beautify our urban environment and begin to reduce our summertime energy consumption. Who knows? In time, Los Angeles may one day become a green city that is as pleasing to the eye as it is to live in during the summer months.
Josh Tickell is an author and filmmaker. His recent book is Kiss the Ground: How the Food You Eat Can Reverse Climate Change, Heal Your Body and Ultimately Save Our World. Visit joshtickell.com
Photos: Carl Studna
This article is a part of the 2018 April / May issue of Whole Life Times.