People love summer and the warm weather it brings, but climate change is increasingly making the summer season a deadly one. In Europe, peak July temperatures usually range from 79 to 83 degrees Fahrenheit (26 to28 degrees Celsius). But during this heat wave peak temperatures have been over 104 degrees Fahrenheit (40 degrees Celsius). In addition, the heat wave pattern we are seeing globally is not only much higher temperatures, but these high temperatures are persisting for longer periods of time.
According to the World Health Organization in the 16 years from 2000 to 2016, an additional 216 million people have been exposed to heat waves, and it’s getting worse. During this current European heat wave Portugal, Spain, Germany and Britain have already accounted for over 4,600 deaths so far in June and July 2022 — and this is not over yet. A full accounting for the number of dead from this heat wave will take several weeks because of the historical delays in reporting these kinds of death. But it is already clear that this will be a significant and tragic event.
Extreme heat from climate change can cause profound direct and indirect impacts on human health. It also exacerbates the health impacts from wildfires and underlying poor air quality. From heat exhaustion, to heat stroke to premature death, our warming planet’s impact is profound and human activity is the cause.
Extreme heat does not impact all populations equally. These disparities occur at the individual, community and societal levels. Individually climate-sensitive people include the very young, very old and pregnant women because they handle extreme heat with more difficulty. Certain underlying medical conditions also put people more at risk. People with cardiovascular, chronic lung disease, diabetes and mental health for example don’t handle the stress of extreme heat well and are often on medications that alter their ability to self-regulate their bodies temperature.
People working in certain occupations that work outdoors or indoors where there are high ambient temperatures are also at increased risk. Examples include farm workers, people who compete or train outdoors, factory and boiler room workers and public safety workers. The indoor conditions can be mitigated by the use of air conditioning, adequate hydration and limiting outside work, training or exercise when the ambient temperature is significantly elevated.
The built environment also influences this health impact. The expanding range of extreme weather in geographic places that are not use to such extremes of heat means that their homes and workplaces were not built to handle high heat conditions. In fact, structures in these places are often built to trap heat because there has been greater concern about colder weather. These communities not built for heat are less likely to include things like air conditioning or other mechanisms to circulate cooler air. In Europe, only 20 percent of homes have air conditioning compared to 88 percent in the United States. That is because before this persistent high heat they rarely needed it even in school or office settings. The environmental risks of exacerbating climate change from the increased use of air conditioning creates a paradox that must be addressed. But during this heat wave protecting people from extreme heat is a priority.
It has been shown that urban communities that are built of a lot of dark impervious surfaces like roofs that absorb rather than reflect the sun’s rays increase the urban heat island effect — trapping heat for longer than rural areas — and increase the ambient temperature of communities. This is even worse in communities that have fewer trees and green spaces when compared to communities with abundant green space. These conditions tend to persist more frequently in lower-income communities so the presence of more dark surfaces and less green space can cause these communities to be as much as 9 degrees Fahrenheit warmer than more affluent ones. Coupled with the disparities that we know exists with chronic health conditions in underserved minorities and low-income people, extreme heat results in significant health inequities. It is to these inequalities that environmental justice advocates are working to demand climate action now.
Indirect health effects are being seen daily from the rash of wildfires caused by the heat and drought conditions. These fires cause not only severe burns, but the air becomes polluted with toxic materials from burned homes and by diminished air quality often miles from the origin of the fire. This also has a negative impact on human health causing more severe respiratory and heart attacks. The inflammation causes by this pollution and wildfires even increases the risk for susceptible people to get infected with infectious pathogens like SARS-Cov-2 the virus that causes COVID-19.
Indirect impacts include the effects of extreme heat on infrastructure such as road surfaces, airport runways, train rails and bridges. All of which can become physically altered in extreme heat conditions and can result in transportation crashes or bridge collapse with concurrent injury and death.
The impact of climate change on our health is clear and unequivocal. It is here now and impacting our health in profound ways. Europe has had this June to July extreme heat wave, while we in the United States are now having our own version in much of the nation. With heat advisories across the country, millions of lives may be at risk. We have a robust suite of mitigation and adaptation solutions in our toolbox — but not the will to act. Lives are at stake. We need aggressive climate action now.
Georges C. Benjamin, MD, is a public health physician and the executive director of the American Public Health Association. He is the former secretary of the Maryland Department of Health and Mental Hygiene.