As summer arrives, numerous news articles about record-breaking heat waves and climate issues flood in. A term that frequently appears is “Heat Wave.” But what exactly is a Heat Wave, and how do they cause problems?

A heat wave is a period of abnormally hot weather generally lasting more than two days. Unlike regular hot weather, a heat wave can last for more than two days or even several weeks, resulting in health problems. Heat waves are caused by various reasons; however, three major causes I will discuss are a high-pressure system, urbanization, and climate change.

A high-pressure system refers to a situation where strong pressure is applied to the air. It pulls air from outside of a specific area and from the upper atmosphere, compressing the air and increasing the pressure. As hot air accumulates and the pressure rises, the temperature in the area increases rapidly, resulting in a heat wave. The reason a high-pressure system is difficult to resolve is because as the temperature rises due to the system, the hot air causes the system to reoccur, prolonging the heat wave. Therefore, it significantly contributes to the severity and continuity of heat waves.

Urbanization, another cause of heat waves, makes summer terrible in a different way. The reason urbanization leads to heat waves is due to the heat island effect. The heat island effect is a phenomena in which city roads and buildings absorb and re-emit more heat than natural landscapes. As a result, cities have higher temperatures than surrounding rural areas. According to the U.S. Environmental Protection Agency, daytime temperatures in urban areas are about 1–7°F higher than temperatures in outlying areas, showing that cities naturally become heat islands with higher temperatures than their surroundings. As temperatures continue to rise, high-pressure systems become more active, perpetuating the cycle of heat waves.

Climate change, particularly global warming, significantly exacerbates heat waves caused by high-pressure systems and urbanization. As global warming raises average temperatures, heat waves occur at even higher temperatures, and their intensity continues to increase. Additionally, warmer temperatures enhance the stability of high-pressure systems, increasing the frequency and severity of heat waves. Some may argue that global warming is not serious, but the Earth’s temperature is continuously rising, and the current warming is happening at a rate not seen in the past 10,000 years. It is an unavoidable fact that as global warming raises temperatures, heat waves will also become hotter and more severe.

Heat waves, sustained by high-pressure systems, urbanization, and climate change, have a profound impact on various living beings, including humans. The extremely high temperatures caused by heat waves can lead to heatstroke in both people and animals, as their bodies cannot withstand the heat. Additionally, the stress on the body from trying to cool down can damage the heart and kidneys. These health issues can lead to economic and social anxiety and negative impacts. Heat waves not only affect people but also cause severe problems such as drought, increased wildfire behavior, hazardous smoke, water insecurity, power shortages, and agricultural losses. The wide-ranging issues caused by heat waves are not just a problem in the United States but a global concern.

News reports often make heat waves sound like an unstoppable and catastrophic problem; however, if people become aware of the causes and impacts of heat waves and pay more attention, it is possible to mitigate their effects, even if we cannot eliminate them entirely. Reducing greenhouse gas emissions and considering green buildings or reflective materials in urban planning to prepare for heat waves are achievable first steps. The key is to not overlook climate issues, including heat waves, as everyday occurrences, but to take an active interest. If people pay a little more attention and demand change, the climate can move in a better direction.

This article was edited by Ipek Unal.