The other week—you remember it, that really steamy one toward the end of August—I found myself in a particularly hot environment. My family and I were conducting our bi-weekly visit to Long Beach’s eastside Target for the essentials (baby stuff, cleaning supplies, and ice cream). After parking a couple hundred feet from the front entrance, we stepped out of the car to find ourselves bombarded with life-sucking heat, similar to what one might imagine in the Gobi Desert. As we made the intolerable trek to the oasis of air-conditioned shopping, I tried to imagine all the factors that contributed to this horrible predicament.

What we were experiencing in our journey across the lot was, in part, what is known as the urban “heat island” effect. This occurs when the sun’s heat is absorbed and then radiated back by the large quantity of dark, non-reflective, impervious surface area, for instance roofs, streets, and parking lots. According to the United States Environmental Protection Agency (EPA), the temperature in urban and suburban areas can be artificially elevated anywhere from two to ten degrees Fahrenheit because of it. Since energy use typically climbs about two percent for every one degree of higher temperatures because of air-conditioning, this “heat island” effect can contribute significantly to energy consumption during hot summer days—about $100 million dollars annually just in Los Angeles (according to the EPA).

Many larger regional and urban planning issues contribute to this heat island effect. Suburban sprawl and other accommodations for cars worsen the effect; compact development as well as reducing surface area dedicated to parking (lodging cars underground, on rooftops, or in multi-story garages) reduce it. Methods typically used to reduce a roof’s contribution to the effect include green roofs (planted areas) and cool roofs (using materials that reflect heat). Some cities (including Chicago and Sacramento) have begun addressing parking lots’ contribution to local “heat islands,” including repaving their surfaces with lighter-colored material, as well as urban forestry programs for parking lots. These sorts of programs could be officially adopted in Long Beach, but could also be implemented more locally as a case study—say, in the parking lot of the eastside Target.

Obviously, trees in a parking lot reduce the sunlight cast on the paved surface, but unfortunately the flowering trees and palm trees often used in parking lots cast little shadow; they are but accents to a lush urban forest design. Trees planted in parking lots should produce good shade and be well maintained (with large planting areas, and plenty of water until thoroughly established). One problem is that commercial tenants typically do not like large trees in a parking lot because it reduces visibility, though this can be addressed through better signage. Planting strips can also be created at the front of each parking space, with a raised curb to stop wheels from rolling onto plants. Doing so on both facing parking stalls, creates a five-foot-wide planter running the length of an entire parking lane.

The area dedicated to parking should be reduced wherever possible, and much can be done without sacrificing precious stalls. For instance, over more than a decade of observation, the eastside Target’s parking lot has never been full; outside the holiday season, the lot does not reach over fifty percent capacity. One strategy might be to turn that underused half of Target’s parking lot into an expansive lawn, using it for overflow parking on those rare occasions when the additional stalls are needed. This strategy is used, for example, in Pasadena around the Rose Bowl, as well as along the Marina Green in downtown Long Beach for large events at the Convention Center. 

In cases like this, the surface area that must remain paved can be done with materials that reduce the absorption and radiation of solar heat. Replacing the dark surfaces of our streets and parking lots with white-cement concrete, for instance, increases reflectivity. Permeable paving materials like degenerated granite or brick pavers also work well to reduce heat absorption in areas used for lower traffic areas like parking.

The additional cost of these strategies might result in resistance from property owners and commercial tenants, but there are obvious longer-term financial benefits for all parties. Reducing the “heat island” effect has consequences for local air quality by decreasing ground-level ozone (smog levels are typically related to increased temperatures). Landscaping also creates a carbon sink that acts as an air filter, reducing local air pollution. Landscaped areas and permeable paving decreases storm water run-off by allowing rain water enter the groundwater aquifer below the property. Up-front costs for improvements—as well as maintenance for landscaping—would likely be offset by savings from reduced use of air conditioning due to lower summer temperatures influenced by the microclimate of the parking lot.

Not everyone sees the long-term benefit of these sorts of improvements, but a growing number of businesses are finding that environmental sustainability is a sound business model. Large corporations are building headquarters that follow sustainability criteria set forth by the United State Green Building Council (USGBC). Leadership in Energy and Environmental Design (LEED) sets forth factors (including site development, building design, and materials) that can reduce energy use and material waste, helping to alleviate the environmental impact of development. The City of Long Beach has recently established its own Green Building Policy which draws from LEED guidelines and stresses the importance of sustainability in new development. In fact, the newest Target in North Long Beach is to follow the City’s interim Green Building Policy. Let us hope that Long Beach’s newest acreage of parking follows some of these sustainable strategies to help reduce its environmental impact.