A park in the heart of Kyiv, Ukraine.
When we think of climate change, we generally think of a global problem, requiring global solutions. International treaties, new methods of manufacturing common goods, and the reduction of corporate carbon emissions all take place on a global scale. But the fight against climate change is not just something taking place in corporate suites and the halls of international organizations—it’s happening in our own cities.
Urban parks are local, community-based efforts to both improve city living conditions and mitigate the effects of a changing climate. Parks, of course, are the heart of municipal neighborhoods around the world. They provide recreational areas, serve as vital gathering spaces and cultural landmarks. In doing so, they directly improve the lives of nearby residents by lessening the impact of climate change.
The most immediate and obvious impact of urban parks is the reduction of heat in surrounding areas. These “cool islands” provide relief from the sun on hot days through both the biological process of evapotranspiration and by increasing shade coverage. Parks located in urban areas are extremely effective at “filtering heat like a sponge” through their branches and leaves. And, parks are proven to significantly reduce air temperature in surrounding areas. The greenery located in parks provides people welcome shade on summer days. Urban areas often lack shaded areas—can you think of many trees lining the streets of downtown San Diego?—so the shade available in parks is crucial for the comfort of local communities. In addition, shade protects people from solar radiation, thus reducing the rates of skin cancer and liver spots.
Parks can also help mitigate the effects of global deforestation. The carbon that would have been absorbed by the downed trees is instead released into the atmosphere, where it has a warming effect on global temperatures. Parks, with their green landscapes and verdant trees, can help. One acre of trees planted effectively cancels out the emissions from driving a car 11,000 miles. Central Park, located in New York City, has 843 acres of mostly covered areas; this adds up to more than 9 million miles canceled out through planting trees.
As the polar ice caps melt and cause the oceans to rise, flooding will become a major concern in seaside cities. The picturesque harbors of Miami and San Diego could be underwater or severely threatened by the year 2100. Parks can absorb floodwater and divert it away from populated areas, so that severe storms do not inundate residential or industrial areas. Plus, parks filter stormwater and ensure that it does not seep into the city’s water supply.
San Diego and its surrounding areas are particularly vulnerable to climate change, and are expected to feel its effects heavily in the decades to come. The region is currently experiencing a drought, and hundreds of square miles within the city are vulnerable to out-of-control wildfires. In addition, the low-lying areas of Coronado and downtown San Diego could be inundated with even a few feet of sea level rise.
The city is also home to tens of thousands of low-income families, who often do not have the money or infrastructure to access air conditioning. This poses a massive public safety issue, especially during the intense heat waves that will only become more common due to global warming. Exacerbating the issue, the areas of San Diego with the highest levels of low-income residents have the fewest number of parks—a crucial disparity that affects the health, wellbeing, and sense of community in these neighborhoods.
The most well-known and largest urban park in San Diego is Balboa Park. Located near downtown, Balboa Park is the nation’s biggest urban park and plays vital environmental and social roles in San Diego. Many of its 15,000 trees are struggling due to drought, but they nonetheless provide important shade and cooling for the downtown area. In this way, Balboa Park acts as a cool island. The city has also recently launched a program to plant new trees there and ensure that the existing ones survive and thrive through efficient water management.
Annually, Balboa Park sequesters 218.5 metric tons of carbon, removes 7.9 metric tons of air pollutants from the downtown area, and collects millions of square meters of water runoff after heavy storms. These vital but often unseen tasks ensure that the San Diego area is safe and pleasant to live in, and that our plant and animal ecosystem will continue to thrive.
In addition to the environmental effects, Balboa Park also provides countless social benefits to San Diego residents. It generates over $350 million annually by attracting tourists—an industry that directly employs thousands of San Diegans. The park’s world-class museums and cultural centers offer educational opportunities to the community. Balboa is home to free and accessible recreational areas like trails, bike paths, sports fields, and a gym. Overall, Balboa Park serves to greatly improve the health and wellbeing of the downtown San Diego community, which, being located in a chronically underfunded urban setting, is not home to many accessible open spaces.
Finally, I’d like to discuss an example of a well-designed, effective urban park located near my home. Black Mountain Park perfectly encapsulates the benefits as well as the difficulties of San Diego urban parks. Its 2,352 acres of mostly wooded areas serve as a terrific community gathering space. Black Mountain boasts dozens of miles of hiking trails, workout equipment, and spaces for parties and events. However, it has also been affected by environmental problems and contamination. The park used to be an arsenic and gold mine—an operation that still causes pollution to run downhill during heavy rain, and caused closures in 2017.
Yes, urban parks have problems. But, they play an important role in mitigating the effects of climate change and providing important social spaces. San Diego, as well as cities around the globe, must invest in parks, and, by extension, local communities and their health.