The 2018 Heat Wave: How can we keep our cities cool?

Every year it seems like this summer was hotter than the last. But the summer of 2018 marked record-breaking high temperatures across the globe, creating a season of emergencies. The heat wave that broke out across North America, Europe, and Asia this year surprised meteorologists and climate scientists alike.

On July 6th, a Los Angeles neighborhood reached a record-breaking 117°F. Peak energy-demand set a new record for July in the city and over 34,000 energy customers experienced outages for up to 24 hours. By the end of June temperatures in Denver had already reached 105°F (1).

The dry and arid conditions across the western United States resulted in wildfires that burned hundreds of thousands of acres of land and almost as many homes. The Mendocino Complex Fire burned over 320,000 acres and had 3,500 firefighters around the clock battling the blaze. It is the largest wildfire in California on record (2). Dry thunderstorms had the Rockies ablaze and even forced Yosemite National Park to close during its top tourist season. Not only do wildfires cause destruction to property and habitat, but the smoke can travel all the way to the east coast, reducing air quality.

Europe and Asia also saw record high temperatures this year. Japan reached a record temperature of 106 °F.  In many parts of Japan, air conditioning is uncommon in schools and homes, and over 70 deaths were reported as heat-related (3). Japan also has one of the highest population of elderly people, with over 33% of citizens being over the age of 65. Senior citizens are far more likely to die of heat-related illness. Climatologists agree that climate change is not going to make things better. But how can we make out cities more comfortable (and livable)?

One of the ways cities are combating high temperatures is by increasing the amount of urban vegetation. That means planting more trees, installing more green walls and vegetative roofs. This summer in Dallas, TX where temperatures soared above 105°F, volunteers and residents in the low-income neighborhood of Oak Cliff planted over 1,000 trees in hopes of combating future heat waves. Seattle, Portland, New York City, and Denver are all working towards encouraging or mandating vegetative roofs on new development (5).

Many cities are also increasing the number of cool roofs (roofs coated with a white reflective surface) to combat the Urban Heat Island caused by so many dark impermeable surfaces. New York City has painted over 5 million square feet of rooftop space with a reflective coating. Some cities (like Los Angeles) are even painting the roads white, which has shown to decrease the ambient temperature by 10-12°F (4). Tokyo is painting many of its road surfaces in preparation for the 2020 Summer Olympic games (5).

Here in Denver, we love the outdoors. We love our parks, our trails, and enjoying a Broncos game in the sun. Massive heat waves like these are a danger to public health and prevent people from enjoying our public spaces. Let's do what we can to help make our city a better (and cooler) place to live.

Sources:

  1. https://en.wikipedia.org/wiki/2018_North_American_heat_wave

  2. https://www.cnbc.com/2018/08/12/more-than-100-large-wildfires-in-us-as-new-blazes-erupt.html

  3. https://www.axios.com/japan-temperatures-reach-all-time-record-high-cda78ab9-b6cb-49bb-b53d-12430de2aef0.html

  4. https://www.cbsnews.com/news/los-angeles-is-painting-some-of-its-streets-white-and-the-reasons-why-are-pretty-cool/

  5. https://www.nytimes.com/2018/07/24/climate/heat-waves-cities.html