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Strategies To Address Heat Waves
Local governments can play an important role in predicting and responding to excessive heat events, or heat waves. Two increasingly common strategies are heat alert systems and heat island reduction measures.
What are Heat Health Watch-Warning Systems?
Heat Health Watch-Warning Systems predict when heat
waves are likely to affect public health, and alert
public officials to this threat. These systems use
computer programs that analyze National Weather Service
forecasts and other local data to forecast dangerous
conditions. Working with the University of Delaware's
Synoptic
Climatology Lab
, approximately 20 cities in the U.S. have
established Heat Health Watch-Warning Systems.
Participating cities include Philadelphia, Seattle,
Chicago, and St. Louis, as well as numerous
municipalities throughout Europe.
Once forecasters determine that a high-risk airmass is approaching a city, they notify local public health departments. At that point, city officials issue a watch, warning, or alert to residents depending on the magnitude of the perceived threat. This prompts local organizations to notify vulnerable citizens - typically older adults, infants, and those without air-conditioning—and initiate appropriate response measures.
Can Heat Island Reduction Strategies Lower the Risk of Excessive Heat Events?
While heat alert systems can lower the risk from heat waves in the short run, communities can also plan for excessive heat over the long term. Research by the University of Delaware and Tulane University suggests that heat island reduction measures implemented on a large scale can alter the meteorology of air masses enough to decrease the incidence of heat-related mortality.
The analysis indicates that increasing city-wide albedo (reflectivity) by 10% or more through the use of lighter-colored surfaces can potentially modify an area's weather during hot summer months. Running this data through computer models used to predict mortality from "oppressive" air masses shows that heat island reduction strategies may decrease the number of deaths during heat waves.
While research relating cooling strategies to heat wave mortality is in its infancy, installing reflective surfaces and planting shade trees are often "no-regrets" strategies. These measures can improve air quality, decrease energy use, and save money from lower electricity use. The potential for lowering risk to public health from excessive heat events is simply another reason for cities to consider heat island reduction strategies.