Traditionally, people living in the Northern Hemisphere would expect September to mark the end of summer and a transition to cooler weather. However, this year, much of the world continues to bake under unprecedented heat waves, offering a glimpse into the future and a warning that the world needs to prepare now. The summer of 2022 saw severe heat waves across much of the Northern Hemisphere. Unusually, the world experienced multiple extreme heat waves in different regions at the same time. A recent study published in the Journal of Climate found that these “concurrent heat waves” have become seven times more likely in the northern half of the world compared to 40 years ago. This year, China endured its most severe heat wave in recorded history, with record-breaking high temperatures. The heat wave also was unusual in its duration, lasting more than 70 days, and its geographic range, affecting multiple parts of the country. On the other side of the Pacific, much of the western and southern US baked in heat. Earlier in the summer, Texas and other parts of the Great Plains experienced one of the most severe summers in the region’s history, with temperatures reaching 46 degrees Celsius in some places and records broken for the most consecutive days of extreme heat. Shifting somewhat geographically, intense heat continued into September, particularly in California, where Sacramento, for example, hit 46 C, setting a new record. For much of California, this is the worst heat wave on record for the month of September and one of the worst heat waves overall. In the future, much of the western, southern and central US is likely to see increasingly intense and frequent heat waves. Europe has also struggled with multiple heat waves this summer. In July, the UK recorded its hottest day ever, with temperatures above 40 C. Continental Europe, especially in the south, also endured high temperatures this summer. Experts have warned that Europe is particularly vulnerable to future heat waves, with extreme temperatures increasing more rapidly in Europe than in many other parts of the Northern Hemisphere. The Middle East is another notable hot spot that is warming faster than much of the world. Several Middle Eastern and Mediterranean countries are projected to heat up particularly quickly, prompting longer, more intense and more frequent heat waves. This summer, parts of Iraq, Kuwait, Iran and Saudi Arabia hit 50 C or higher. Other parts of the world are hardly immune. South Asia experienced a major heat wave earlier in 2022, which contributed to the current catastrophic flooding in Pakistan. Earlier this summer, Tokyo endured its most severe heat wave since records began in the 1870s. In January, during the Southern Hemisphere’s summer, Australia and South America experienced historic heat waves, with the Australian town of Onslow hitting 50.7 C. Anthropogenic climate change is making heat waves more likely, while intensifying their temperatures and duration Kerry Boyd Anderson Extensive scientific research clearly demonstrates that anthropogenic climate change is making heat waves more likely, while intensifying their temperatures and duration. As the planet warms, heat waves become more common and severe. In the future, record-breaking heat waves like those of 2022 are likely to be a regular event; indeed, they are likely to get even worse. The consequences are severe. Heat is the most deadly weather phenomenon in many developed and less-developed countries and this year’s heat waves have killed thousands of people and threatened millions more. Heat waves help to fuel droughts and wildfires. Rivers dried up this summer in Europe, China and the US, revealing shipwrecks, dinosaur footprints and archaeological sites. Europe, China, the western US and even parts of the Middle East battled wildfires, with Europe facing one of its worst summers for fire. Beyond the immediate toll on humans and the environment, the economic consequences are significant. Drought and heat undermine hydroelectricity production while increasing demand for electricity. China had to close multiple factories and businesses and ration power due to drought and heat. California and Texas called on consumers to reduce electricity use in order to prevent blackouts. In the Middle East, many Iraqis went through electricity cutoffs and have experienced health impacts from heat and related poor air quality. Heat and its impacts have led to protests in Iraq and Iran. Extreme heat damages transportation networks by drying up rivers used for commerce, melting roads and airport runways and warping railroad tracks. Heat waves reduce agricultural production. Frequent heat waves over several years prompt migration, as people abandon failing farms or otherwise move to places they perceive as more habitable. Governments, communities, businesses and individuals need to adjust the way they think about heat waves. They are dangerous and deadly. They appear less dramatic than hurricanes, earthquakes and volcanic eruptions, but they are no less lethal. The temperature is only one factor; the heat index — how the body feels in response to the combination of humidity levels and temperatures — has a bigger impact on human health. It is also important to recognize that there will be seasons without extreme heat waves, but an occasional mild summer does not mean that the climate is not changing and that heat waves are not a threat. People are not helpless. Governments and societies need to work together to immediately address climate change in order to mitigate its long-term impacts. We also need to recognize that the impacts are already here and will worsen. Governments and communities need to act now to improve long-term resilience, especially in cities, which face particularly acute challenges. Changes in urban planning, labor regulations, healthcare, education and caring for society’s more vulnerable people are urgently needed. • Kerry Boyd Anderson is a writer and political risk consultant with more than 18 years of experience as a professional analyst of international security issues and Middle East political and business risk. Her previous positions include deputy director for advisory with Oxford Analytica. Twitter: @KBAresearch