GCCA partnered with the American Council for an Energy Efficient Economy (ACEEE) partnered to survey 26 North American cities to better understand how cities are tackling the challenges of urban heat. The survey finds that confronting the challenges of extreme weather, adapting to a changing climate, and improving the health and resiliency of urban populations are driving cities to develop and implement strategies to reduce excess urban heat.
Nearly two thirds of the cities surveyed cited local extreme weather events as a key reason for initiating urban heat island mitigation strategies. U.S. cities are waking up to the growing threat of urban heat and employing a number of innovative approaches suited to their location and priorities and we hope the report will help local planners adapt these practices to even more communities across the country.
ACEEE and GCCA surveyed 26 cities in the U.S. and Canada representing all of the major climate zones, geographies, and city sizes. Despite the diversity of the respondents, several common themes emerged. Local governments are leading by example by requiring use of cool technologies, such as reflective roofs on municipal buildings, lining city streets with shade trees, and raising public awareness. Additionally, more than half of the cities have some kind of requirement in place for reflective and vegetated roofing for private sector buildings. Almost every city had policies to increase tree canopy and manage storm water.
The report finds that by addressing their urban heat islands, cities are more effectively delivering core public health and safety services, making them attractive places to live, work, and play.
The report includes case studies on how several cities have responded to urban heat, demonstrating the variety of strategies employed. In response to a study that found that Houston’s roofs and pavements can reach 160°F, the city now requires most flat roofs in the city to be reflective. After an extreme heat wave in 2008, Cincinnati lost much of its urban canopy, and instituted an aggressive forestry plan. Washington D.C. has instituted a wide suite of programs such as Green Alleys,which helps residents manage excess stormwater by replacing pavement with grass and trees, and requiring reflective roofs on all new buildings.
The survey also found that most city governments are not acting alone to reduce excess heat. States, neighboring jurisdictions, utilities, developers, contractors, and local building owners are collaborating to create incentives for communities to reduce urban heat and mainstream these practices.
Cities surveyed in the report include: Albuquerque, NM; Atlanta, GA; Austin, TX; Baltimore, MD; Boston, MA; Charlotte, NC; Chicago, IL; Chula Vista, CA; Cincinnati, OH; Dallas, TX; Denver, CO; Houston, TX; Las Vegas, NV; Los Angeles, CA; Louisville, KY; New Orleans, LA; New York, NY; Omaha, NE; Philadelphia, PA; Phoenix, AZ; Portland, OR; Sacramento, CA; St. Louis, MO, Toronto, ON; Vancouver, BC; and Washington, DC.
The survey is available on the Cool Roofs and Pavements Toolkit: http://www.coolrooftoolkit.org/knowledgebase/cool-policies-for-cool-cities/