Growing Trees to Shrink Salt Lake City’s Heat Islands

2023-07-13T09:15:00+00:00

In the fiery heat of Summer, shade-providing trees are a sought-after resource. They provide us with relief from the heat and they lower overall temperatures in the immediate area. While concrete, roads, and metal absorb and re-emit heat, trees provide substantial relief from the heat by both providing shade and cooling through evapotranspiration. A healthy urban forest is one of our greatest tools in reducing the heat island effect generated by our concrete jungle.

Urban heat islands are caused by a lack of cooling abiotic factors in an environment in addition to abundant human activity. Although minimally perceptible on a small scale, the heat generated by individuals driving, using machinery, or even just jogging builds up, leading to a significant heat increase in the local area. In densely populated urban areas, the heat generated by just living our day-to-day lives with the heat trapped by urban structures accumulates, creating a sweltering heat zone.

Cities overall are much hotter than surrounding rural areas, because of comparably higher levels of human activity and lower square-footage of greenspace. Within cities too, there are areas that have far fewer trees, which leads to even higher temperatures than the rest of the city. This phenomenon is immediately noticeable in Salt Lake City, where shaded areas - like Sugar House or Capitol Hill - feel notably cooler than areas with fewer trees – like Rose Park or Poplar Grove. Although the difference in temperature in these areas might only be a couple degrees, this seemingly small increase in temperature is drastic, especially when the daily temps are reaching the triple digits. With only a 2° increase, energy demands can increase up to 9%, leading to higher energy costs and more pollution.

By growing the urban forest and minimizing these barren, extreme heat zones, we all benefit. We all benefit from lowering temperatures within the cityscape, reducing energy use, and creating welcoming spaces for us all to enjoy year-round. In addition to creating an overall more inviting city for us all to enjoy, we can help protect our neighbors from heat-related illness, keep our waterways clean, and reduce pollution – all by planting more trees. With Salt Lake City’s increased efforts to plant more trees on the West Side and TreeUtah’s partnerships with community organizations in areas in need of more trees, the city’s urban forest will continue to grow and, hopefully, help our community thrive equitably.

No Shade, No Gains

2022-03-30T14:45:14+00:00

There is a Chinese proverb that says, “the best time to plant a tree is twenty years ago. The second best time is now”.

Trees are complex beautiful things that provide us benefits we may take for granted without realizing it. They are mighty carbon warriors who take in excess carbon out of the atmosphere and in turn oxygenate our earth. Trees are also great creators of shade, our protectors against the sun’s rays when it gets too much. Shade from tree canopy, however, is not distributed equitably here in Salt Lake City and the effects are substantially felt on the west side. At TreeUtah we are working to plant more trees each year through our West Side Initiative. All people have a right to nature and we are initiating change by planting trees.

The inaccessibility of tree canopy coverage in an urban environment inevitably leads to consequences from the heat island effect. The heat island effect is not new, but as we increasingly urbanize now and in years down the line, areas will experience higher overall temperatures (up to 25 degrees Fahrenheit more during the hottest afternoons) if greenspace is not prioritized and dark surfaces like asphalt and buildings become more dominant.

Adding trees into spaces, however, will mitigate a common concern in urban areas which is ground-level ozone. Ground-level ozone is a harmful pollutant made from the interaction of the sun, volatile organic compounds found in common household products, and nitrogen oxide from car exhaust. Experiencing hotter days because of climate change and the urban heat island certainly does not help our ground-level ozone levels. With one of the benefits of trees being that they lower air pollution, trees are one solution to improve ground-level ozone and help individuals who are medically sensitive or who may be prone to suffer from illnesses correlated to bad air quality.

Adding things like trees in areas will also foster a sense of place and belonging for individuals because of bringing people together in outdoor spaces that seem more inviting. For further info on the social, environmental, and economic benefits provided to us each day by trees, check out our about page.

Not that long ago, the pandemic started to change the way we work. With workplace culture increasingly switching to remote, people are gravitating toward spending more time outside and participating in outdoor activities. However, we cannot reap the ultimate benefits from these experiences if basic things such as tree cover and green space are lacking. These benefits that trees provide us like improving air quality, helping the heat island, along with the change in our time spent in nature, all build up to why trees are so important in planting equitably on the streets and in places like Title I schools. Our West Side Initiative coincides with Mayor Mendenhall’s four year plan of planting an additional 1,000 trees just on the west side of Salt Lake City each year. Keep your eye out for our next community tree planting on the west side by keeping up to date on our events.

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Growing Trees to Shrink Salt Lake City’s Heat Islands

No Shade, No Gains