What is the real relationship between heat waves and rising air pollution, especially with carbon dioxide? » Yale Climate Connection

A reader asked us:

What is the real relationship between heat waves and rising air pollution, especially with carbon dioxide?

We asked reporter Johnny Ponce to help answer that question. This is his answer:

Heat waves have increased in frequency and intensity in recent years, affecting the daily lives of millions of people around the world. These extreme temperatures can cause health problems, such as heat stroke and dehydration.

Heat waves directly affect air quality and increase pollution in cities and urban areas. While carbon dioxide is not the only cause of deteriorating air quality, its role as a greenhouse gas is crucial.

A 2022 World Health Organization study highlights that heat waves and poor air quality are responsible for thousands of premature deaths around the world.

Carbon dioxide, heat waves and public health

Although the presence of carbon dioxide in the atmosphere itself is not toxic, its accumulation can lead to increased heat waves that exacerbate other types of air pollution. For example, volatile organic compounds and nitrogen oxides released by vehicles and factories react faster with heat, producing higher levels of ozone and smog. This results in atmospheric conditions that directly impact human health, especially vulnerable groups such as the elderly, children and people with respiratory illnesses.

The increased heat favors the formation of tropospheric ozone, a type of ozone found in the lower layers of the atmosphere near the Earth's surface. This ozone is a dangerous pollutant because it can irritate the lungs, make breathing difficult, and worsen respiratory conditions such as asthma. In addition, heat increases energy consumption, leading to more carbon dioxide emissions and other air pollutants.

The amplifying effect of heat on air pollution

Some air pollutants increase with heat, including those released by vehicles and factories, which react with sunlight to form ground-level ozone, which is harmful to health. Fine aerosol particles (PM2.5) produced by vehicles, factories and fires can exacerbate respiratory and cardiovascular problems.

The Intergovernmental Panel on Climate Change report concluded that the transition to clean energy is critical to reducing carbon dioxide emissions and curbing the effects of climate change, including increased heat waves.

vicious circle

Heat increases energy consumption primarily by increasing the demand on cooling systems such as air conditioners and fans. During a heat wave, people tend to use more electricity to keep their homes and workplaces comfortable. Additionally, extreme heat increases energy consumption in other sectors, such as industry, as factory cooling systems require more energy to operate at high temperatures.

Carbon dioxide causes global warming by trapping heat in the atmosphere, causing temperatures to rise and exacerbating heat waves. This dangerous cycle has multiple consequences.

Increases in atmospheric carbon dioxide are directly linked to rising global temperatures, leading to more frequent extreme weather events, including heat waves.