Combatting Urban Heat Islands and its Effects
Currently, urban heat is a significant issue that threatens the health and well-being of numerous cities around the world. Urban heat or urban heat islands are cities that are significantly warmer than its surrounding areas. The extensive heat comes from the removal of trees and vegetation and replacement of asphalt and other heat absorbing surfaces that are found in cities. These urban heat islands can have a major negative impact on not only people, but infrastructure, economies and other ecosystems. So what really is and causes urban heat islands and what are our solutions?
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The cause of urban heat lies within climate change and urbanization. Currently, climate change has caused frequent and intensifying heat waves around the world. In cities especially, temperatures have risen significantly. For example, a Pacific Northwest heatwave in 2021 created Portland and Seattle to reach record breaking temperatures of 116°F and 108°F, respectively. Urbanization causes heat islands by getting rid of vegetation and replacing them with roads, buildings and other heat absorbing surfaces. This can end up increasing temperatures by up to 44°F during the day. Not to mention these heat islands can also worsen air quality.
There are many potential risks that coincide with the creation of urban heat islands. Public health risks such as heat stress, exhaustion, stroke, dehydration and even cardiovascular and respiratory issues. The intensified heat can also worsen pre-existing chronic health conditions, like diabetes and asthma. Between the years of 1998 to 2017 it is recorded that roughly 166,000 people have died due to heat.
UHI can also result in infrastructure damage such as roads, bridges, water pipes and more to crack, melt or burst. The heat even heightens the risk of wildfires in these areas.
There can also be economic upsets from urban heat islands. For instance, it reduces work productivity. It also increases energy costs and demand for cooling, which can result in blackouts.
While these effects may seem scary and with the current state of the Earth, seems unavoidable, there are many solutions and success stories aimed at reversing urban heat islands.
Planting trees and green coverage can increase shade that will help lower the overall temperature of the island. Recently, Singapore planted over seven million trees and hundreds of new parks and gardens to cool the city.
Installing green or cooling roofs can both reduce building heat, lower energy consumption and improve urban biodiversity. New York City has done a good job with this tactic by installing over 10 million square ft of roofing in the last 2 decades.
Asphalt which is a major cause of the heat islands can be replaced with cool pavement. This type of pavement had a higher reflectivity and permeability. Since 2017, Los Angeles has been testing cool pavement and revealed that it can lower surface temperature immensely.
Other strategies for protecting people from the intensified heat is the establishment of cooling centers, ensuring access to indoor cooling and protecting outdoor workers.
Urban heat is a prominent global issue that leads to numerous negative effects. However, there have been multiple projects and strategies around the world that have given hope to reversing urban heat islands and its effects.
