Heat Waves

July 2023 has been the hottest month on record. Not just the hottest July. The hottest month, period. In fact, 2023 is currently on track to replace 2016 as the hottest year since records began in 1850. The world is currently in a multiyear period of extreme warmth – the past eight years are the eight hottest on record – and unusual weather events, such as heat waves, extreme rainfall, droughts, cold spells, and wildfires, are all on the rise globally. The Southwest United States and Mexico, Southern Europe, and China have all experienced unprecedented temperatures in the past month, with temperatures over 50ºC (122ºF) in Death Valley, USA, and Northwest China. The record for the highest recorded temperature in China was broken on July 16th in Sanbao and nighttime temperatures reached unusual highs in Spain, Arizona, and the Cayman Islands.

The World Weather Attribution characterizes heat waves as one of the deadliest natural hazards. Thousands die from heat-related causes each year, a figure that will only rise as the state of the climate worsens. The full impact of a heat wave on a person’s health may not be known until weeks or months after the exceptionally high temperatures occur, but hot nights can be especially detrimental to health because the human body needs to cool off at night after a hot day. In the Southwest United States and Mexico, hundreds of heat deaths have already been confirmed and many of the victims have been migrants near the border between the two countries.

Without human-induced climate change, heat waves like the one experienced this month in Northwest China would have happened approximately once every 250 years. Now, they are projected to occur once every five years. In the Southwest United States, the highs that have been experienced this summer would be virtually impossible without global warming. Going forward, they will likely occur at least once every fifteen years. Since the 1960s, the number of heat waves experienced annually in the U.S. has tripled, and these heat waves have become both longer and more severe. Global heat waves of a similar scale are projected to occur every two to five years in a world that is 2ºC warmer than pre-industrial temperatures,  so unless we rapidly stop burning fossil fuels, dangerous heat waves like the ones experienced this summer will only become more common.

So, what can be done to combat heat waves and prepare for the future? Heat action plans have already been put in place in the Southwest U.S., Southern Europe, and China, but there is still an urgent need to improve urban preparedness for extreme heat worldwide. Cities must accelerate the roll-out of initiatives to deal with unusually high temperatures, as, going forward, these temperatures may become less and less unusual. Heat island reduction strategies, like cool roofs, cool pavements, and increased vegetation in urban areas, will work to reduce extreme temperatures during future heat waves, which can be especially dangerous in densely-populated urban areas. As the frequency and severity of heat waves increase, sound urban planning will become essential in maintaining safe living conditions and high quality of life in cities across the world. Heat waves are, unfortunately, a part of today’s climate and, as a global community, we must be prepared for the consequences.

Written by Aoife Beswick

Edited by Ayah Mallah

Works Cited:

Al Jazeera. "Extreme Weather: What You Need to Know about the Global Heatwave." July 17, 2023. Accessed July 28, 2023. https://www.aljazeera.com/news/2023/7/17/extreme-weather-what-you-need-to-know-about-the-global-heatwave.

Extreme Heat in North America, Europe and China in July 2023 Made Much More Likely by Climate Change. July 25, 2023. Accessed July 28, 2023. https://www.worldweatherattribution.org/extreme-heat-in-north-america-europe-and-china-in-july-2023-made-much-more-likely-by-climate-change/.

United States Environmental Protection Agency. Climate Change Indicators: Heat Waves. Accessed July 28, 2023. https://www.epa.gov/climate-indicators/climate-change-indicators-heat-waves.

United States Environmental Protection Agency. Heat Islands. Accessed July 28, 2023. https://www.epa.gov/heatislands/adapting-heat#:~:text=Programs%20that%20install%20cool%20or,system%2C%20particularly%20during%20heat%20waves.

Zhang, Raymond. "This Looks like Earth's Warmest Month. Hotter Ones Appear to Be in Store." The New York Times (New York, NY), July 27, 2023. Accessed July 28, 2023. https://www.nytimes.com/2023/07/27/climate/july-heat-hottest-month.html?searchResultP