Rising temperatures, especially overnight, is reducing the amount of sleep people get worldwide, new research shows. The global study published in One Earth tracked the sleep of 47,000 people in 68 countries for a combined 7 million nights and found humans are each losing an average 44 hours of sleep per year, leading to 11 fewer days in which they get the recommended 7 hours of sleep per night. Women, the elderly, and people in lower-income countries lost 25%, double, and triple the global average, respectively.
Global warming, mainly caused by the extraction and combustion of fossil fuels, is heating overnight temperatures even faster than during the day, and since people’s bodies need to cool at night as they fall asleep, warmer temperatures are delaying that process. “Worryingly, we also found evidence that people already living in warmer climates experienced greater sleep erosion per degree of temperature rise,” Kelton Minor, lead author of the study, told The Guardian. “We had expected those individuals to be better adapted.” (The Guardian, Grist, The Hill, New Scientist, E&E News; Climate Signals background: Extreme heat and heatwaves)