Urban Heat Islands


Shade trees are important to our health for many different reasons. In the summer one of those reasons is shading our urban surfaces.

“To accommodate growing populations, cities have large areas of paved concrete and asphalt surfaces that create ‘urban heat islands (UHI)’. These hard surfaces absorb large amounts of heat that builds up during the day and is released at night, leading to much higher night temperatures in cities than in surrounding areas.”

“The good news is that trees offer many benefits that offset the impacts of UHIs. Cities with larger tree canopies are a testament to this fact and have fewer adverse impacts from UHIs than do cities with low tree canopies.”

“Trees reduce the impact of UHIs by releasing heat back into the atmosphere faster than do concrete and asphalt surfaces. In addition, well-placed trees produce shade that cools the surrounding environment and reduces air conditioning needs. They also cool the air through transpiration and absorb and store carbon which moderates the impacts of pollution from fossil fuels.”

Our larger trees that provide a lot of the shade in our urban environments are at the end of their lifespan. If we don’t plant replacement trees we will notice an increase in temperature in some of our urban environments.

Cheyenne Urban Forestry is currently trying to offset this effect in the downtown area by planting as many trees as possible. In the future, a robust tree canopy downtown will provide shade for the hard surfaces as well as reduce utility costs for businesses. More shade is also more conducive to more pedestrian traffic. More pedestrian traffic means more sales for downtown businesses.

Trees are important for many different reasons. Reducing these urban heat islands is a benefit that helps everyone in the community.

Reference:

The Orange County Register, Janet Hartin, UC Cooperative Extension, https://www.ocregister.com/2019/06/11/why-planting-shade-trees-helps-reduce-the-temperature-of-urban-heat-islands/