Exposure to extreme heat grew drastically in the world’s cities
Exposure to dangerous levels of heat and humidity in cities across the world has exploded over the past three decades, according to new research. In a study of more than 13,000 cities, the number of people exposed to extremely hot and humid days in a given year (measured in “person-days”) tripled between 1983 and 2016.
It’s a symptom of two trends colliding: urban population growth and rising global average temperatures. Cities often reach higher temperatures than surrounding rural areas because they’re typically designed in a way that traps heat. So when people flock to urban centers, they’re also flocking to places where they could be at greater risk of heat-related illness and...