Heat waves and their impacts
It’s that time of the year. The kids are on school vacation, the sun is shining, and the beaches are packed with people, umbrellas, and sand castles. But it’s also the time of year for heat waves, and unfortunately heat waves are happening more often and lasting longer due to global climate change. Heat waves have negative consequences for public health and put an enormous strain on the electric grid and water supply. As I write this very article, heat waves are active across the globe. Thirty-three people have died from a record-breaking heat wave in Quebec, over 12,000 people are without power in Los Angeles after a heat wave induced black out, and a current heat wave in the United Kingdom is projected to last another week.
The risk caused by heat waves has led to research on adaptation techniques and policies that can be instituted to protect public health during these extreme temperature events. The most common strategy employed when the temperatures become scorching is to encourage the use of air conditioning. While air conditioning can provide comfort to people and pets, it does not come without costs. High air conditioning usage strains the electric grid, and can lead to heat wave caused power outages, such as the one in Los Angeles mentioned above. Air conditioners also contribute to urban warming. While it might seem counter intuitive, the way your air conditioner works is by rejecting hot air (i.e. keeping it outside), which leads to increased outdoor air temperatures. This is especially true in urban areas where large populations live in a restricted radius. Another major consequence of heat waves is an increase in water consumption, especially during peak hours.
Strategies for coping with heat waves
With drought and heatwaves predicted to increase in the future as a result of climate change, it is necessary to adopt strategies to cope with heat stress while conserving energy and water. Spurred by the need to develop policies to mitigate heat wave stress, Gertrud Hatvano-Kovacs and her colleagues from the University of South Australia recently published a study that details research on heat stress adaptations and provides policy recommendations for the future. Hatvani-Kovacs and her colleagues break up the policy recommendations into four main areas: public health services, building and construction industry, urban planning, and infrastructure and utilities.
1. Public health services
Hatvani-Kovacs and her colleagues suggest that the primary way that public health services can decrease the impact of heat waves on public well-being is through education. In particular, they suggest targeted alerts, such as alerts sent from primary care physicians to people with health conditions that could predispose them to issues during a heat wave. The authors further suggested using social media to present alerts and distributing information regarding the risks of activity outdoors during a heat wave to the public. A critical aspect of the alert system is having accurate forecasts that are based on models that incorporate climate change, which is not currently the norm. Lastly, public cooling centers should be utilized in order to provide relief to those that do not have access to climate-controlled environments.
2. Building and construction industry
There are several policies that Hatvani-Kovacs and her colleagues suggest to lower the strain on the electric grid and water system due to high demand during heat waves. For example, providing incentives for homeowners to install solar panels can reduce demand for electricity that is won using traditional methods (i.e. fossil fuel burning) during peak hours. Passing ordinances or regulations that require light colored roofs, which reflect solar energy, could also have an impact on urban warming. Lastly, public buildings could be retrofitted to showcase heat stress resistant buildings and encourage changes in building practices.
Hatvani-Kovacs and her colleagues also suggest requiring energy performance certificates when a property is sold or rented. These certificates would outline the heat stress resistance of the property and what potential renovations could be done to increase the resistance. Programs similar to these certificates are currently in use in a variety of areas, including in the European Union, and have been shown to increase property values of energy efficient homes. Certificates may provide the proper incentive for homeowners to adopt renovations and alterations to increase the heat stress resistance of their properties.
3. Urban planning
Ensuring that there is adequate vegetation and green space in urban environments can reduce the outdoor air temperature. Shaded areas can be 20-45 degrees Fahrenheit (11-25 degrees Celsius) cooler than unshaded areas during peak temperatures. Hatvani-Kovacs and her colleagues suggest that policies should require a minimum amount of green space in between homes to promote cooling by vegetation, which can also reduce the need for cooling indoors. Furthermore, strategically planting trees throughout urban areas can also help lower air temperatures.
4. Infrastructure and utilities
Lastly, Hatvani-Kovacs and her colleagues propose policies that impose variable electric and water tariffs to restrict usage, building commercial batteries to store energy that can be utilized during heat waves, and implementing water-wise and electricity-wise programs. These “wise” programs would provide instructions on when to reduce water or electricity demand. For example, it would explain that lawns should not be watered during the peak hours of the day and appliances such as dishwashers should not be used during peak hours of electricity demand.
While not all policy recommendations from Hatvani-Kovacs and her colleagues will work for all situations, it is clear that the future will be hotter for longer and strategies to cope with heat waves should be implemented now. Furthermore, using a holistic approach by creating working groups that have members from all of the relevant offices will produce more effective outcomes than if each office implements separate policies. So, what can you do? Check out these resources on water conservation (US EPA, Town of Waltham) and energy efficiency (US DOE, Colorado State Extension). If you are remodeling your home, consider ways that you can increase the heat stress resistance of your home. Remember, if we all make small changes they combine to make meaningful changes for our communities.
Hatvani-Kovacs, Gertrud, Judy Bush, Ehsan Sharifi, and John Boland. 2018. Policy recommendations to increase urban heat stress resilience. Urban Climate 25: 51-63. https://doi.org/10.1016/j.uclim.2018.05.001