The Northern Hemisphere is heading into what will surely be another of the hottest summers on record. Texas has already seen more days registering about 90 degrees Fahrenheit in May than ever before in recorded history. The weekend before Memorial Day—the typical start of summer weather—saw heat advisories issued across the United States, from Massachusetts to Mississippi. Meanwhile, temperatures in India and Pakistan have topped 122 degrees Fahrenheit. In May, the UK Meteorological Office issued a study documenting that greenhouse gas emissions had increased the likelihood of extreme heat waves in Pakistan and India by a factor of about 100. Heat now threatens humans’ ability to survive in whole swaths of the globe.
And yet this year’s temperature spike is just the beginning: a rise in temperatures over the next 30 years is all but inevitable. According to the United Nations Intergovernmental Panel on Climate Change (IPCC), this heating trend will continue even if countries immediately slash their carbon emissions to zero. Any reductions in emissions will merely stave off the worst effects of global heating—and it is far from assured that countries will take the steps needed to do so.
Rising temperatures kill. During a heat wave in June 2021, roughly 600 people in Washington and Oregon died from causes likely due to or exacerbated by rising temperatures. The same heat dome killed more than 500 people in British Columbia, not to mention some one billion marine animals. Extreme weather also damages infrastructure, buckling roads and bending rail lines. Most airplanes cannot take off above 120 degrees Fahrenheit, and mobile phones cease to function when the temperature hits 105 degrees.
Global warming is already harming the current and future U.S. workforce. Extreme heat costs the United States more than $100 billion per year due to reduced worker productivity: people get sick, slow down, and make mistakes due to the physical effects of heat. Children’s school performance can decline as temperatures soar. According to researchers at the University of California at Los Angeles, each one degree Fahrenheit increase in temperature during the academic school year reduces the amount learned that year by one percent—and students from low-income and minority groups are the ones most affected.
City dwellers—some 55 percent of the world’s population, or about 4.2 billion people—are especially vulnerable to the effects of climate change. The asphalt, cement, glass, and steel that are features of most urban areas are especially efficient at absorbing, retaining, and emanating heat. The so-called heat island effect can cause temperatures up to seven degrees Fahrenheit hotter in urban environments than in suburbs and rural regions, which have more green space and foliage.
A relatively simple way in which cities can protect their residents is by putting someone in charge of responding to the most harmful effects of climate change. After all, cities have departments for fighting fires and for coordinating responses to regional floods, earthquakes, and hurricanes. But just a handful of cities in the world have someone whose job it is to craft and implement plans to respond to rising temperatures. To save lives, every municipal leader should appoint a chief heat officer, or CHO.
A Rising Trend
In 2020, the city of Miami hired a chief heat officer—the first position of its kind in the world. Since then, Phoenix—one of the most rapidly heating cities in the United States—funded an Office of Heat Response and Mitigation. Athens hired its CHO last summer, as did Freetown, Sierra Leone. Monterrey, Mexico, and the Metropolitan region of Santiago, Chile, followed suit in spring of 2022.
My organization, the Adrienne Arsht–Rockefeller Foundation Resilience Center, crafted the idea of a CHO with Daniella Levine Cava, Mayor of Miami-Dade County, Florida. We then set out to establish one CHO on every continent to serve as a model and hub for best practices to address heat risks. CHOs do not have a uniform remit. Cities’ populations and their vulnerabilities, geographies, weather patterns, and water sources are all different. What works in Vancouver might not work in Los Angeles. For this reason, a CHO’s work must be tailored to the needs of a city’s neighborhoods and population.
To save lives, every municipal leader should appoint a chief heat officer.
In some cases, CHOs will find that a vital step they must take to protect their residents is to overhaul their system of data collection. That was the experience of Miami CHO Jane Gilbert. As in many parts of the United States, Miami’s primary weather station and temperature monitors were located at its airport. Many of Miami’s poorer, most at-risk residents, however, live in treeless, asphalt-heavy neighborhoods that regularly register temperatures five or even ten degrees hotter. Gilbert worked with volunteers and scholars at the University of Miami and at Florida International University to place sensors throughout Miami-Dade County to capture the temperature differentials. These readings are reported on the news and over the radio, so that residents can prepare for extreme temperatures and seek out cool places on the hottest days.
CHOs outside the United States have also launched programs that offer lessons for U.S. municipal leaders. The CHO of Athens, Eleni Myrivili, has compiled a regional cooling guidebook that highlights technical recommendations for specific tree species and their location, and placement of green spaces such as parks. It includes designs for adding water—including pop-up water features and streams—to public spaces. The overall goal of Myrivili’s guide is to give community leaders the information that they need to prepare for a hotter world and to equip urban planners, procurement teams, engineers, and contractors with new ways of approaching municipal design.
In Freetown, Sierra Leone, the city’s CHO, Eugenia Kargbo, is enlisting some 2,000 women who work in unshaded market stalls throughout the city to design structures to protect their workplaces from the sun. Kargbo’s hope is that this will not just help women in the markets cope with the effects of heat but also help spread awareness about the risks that high temperatures pose to families across the city. A particular challenge for Freetown is the rising number of torrential rainstorms, which have increased the incidence of waterborne diseases such as bacterial infections. Kargbo is working closely with Freetown’s sanitation department to address these public health impacts by hosting community workshops to inform residents and brainstorming responses in conjunction with the city’s sanitation team.
Kargbo’s work in this area calls to mind the late 1800s, when cities were first forming public health and fire departments. Municipalities, of course, worked to address disease and fires before these entities existed, but they generally did so in an ad hoc manner. Only once they created an organizational structure to deal with the challenges could they systematically tackle the problem and its root causes. Without fire departments coordinating responses, conflagrations burned out of control. But once departments became a mainstay of city government, big burns became far rarer.
Rally the People
Enlisting members of the community to address the challenge of extreme heat can help protect vulnerable urban residents. In Miami, for example, Gilbert created a “heat enhancement” training program for emergency response volunteers. At the end of each training, participants receive a tool kit containing a thermometer, instant ice packs, electrolytes, and cooling towels so they can treat victims of heat stroke. Making this a national initiative would save lives. Often, the people most vulnerable to extreme heat do not consider themselves at risk, and thus don’t heed warnings. Expanding the number of people who can provide first aid would allow for treatment in cases where medical personnel aren’t present and cannot arrive at the scene quickly.
Community outreach will also help raise awareness about the dangers of extreme heat—which is, in many ways, an invisible problem. Unlike hurricanes and tornadoes, heat waves don’t make for dramatic television. But like storms, heat waves are discrete events that can be planned for. Naming and categorizing heat waves would help draw more public attention to the phenomenon and is currently being tested in six cities including Athens, Greece and Seville, Spain.
As hot as this year will be, it will also be one of the coolest for at least the next century. Urban dwellers—who compose 86 percent of the U.S. population—are at particular risk. Mayors and city leaders would do well to appoint CHOs and empower them to do the hard and necessary work to help populations survive deadly rising temperatures and tack toward a cooler future.
