Warm Nights Disrupting Sleep: The Hidden Impact of Climate Change
Amidst the pressing challenges posed by climate change, a less obvious but significant consequence is coming to light: its impact on sleep. As nighttime temperatures climb, a new study by Climate Central reveals a concerning pattern—people are losing more sleep due to warmer nights.
Research conducted between 2020 and 2025 indicates that individuals worldwide lost an average of 56 hours of sleep annually because of increased nighttime heat. Of these, approximately six hours are attributed to climate change-related warming, highlighting a growing issue as global temperatures rise.
The analysis, which covered 1,338 cities globally, utilized counterfactual scenarios to estimate temperature conditions without human-induced warming. The results underscore that sleep reduction due to warmer nights is a widespread issue, not confined to a specific region.
Understanding the Sleep-Climate Connection
The body’s natural cooling mechanism is essential for sleep initiation and maintenance. When nighttime temperatures remain high, this process is disrupted, delaying sleep onset and causing frequent awakenings. Adults over 65, women, and residents of low- and middle-income countries face heightened vulnerability.
Cities experience exacerbated effects due to the urban heat island phenomenon, where developed areas retain more heat than rural surroundings. This combination of urbanization and climate change ensures that city nights remain unpleasantly warm.
Latin American Cities Feel the Heat
In Latin America, cities like Cartagena, Colombia, face significant sleep loss—up to 91 hours annually due to higher nighttime temperatures. Other cities, such as Barranquilla and Cali, also report sleep reductions of 93 and 61 hours respectively. Similar trends are seen in Cancún, Mexico, and Belém, Brazil.
While high temperatures contribute to sleep loss, distinguishing the portion caused by climate change is crucial. Climate Central’s analysis identifies that climate change accounts for about six of the 56 lost hours globally, with some regions experiencing even greater impacts.
In places like Saudi Arabia, Oman, and the UAE, sleep loss ranges from 55 to 87 hours per year, with 12 to 16 hours directly linked to climate change. Parts of southern India and Southeast Asia report annual sleep loss between 78 and 91 hours.
Doubling Sleep Loss Since the 1970s
Comparative analysis reveals that since the 1970s, climate change’s contribution to temperature-induced sleep loss has doubled in 1,335 cities and tripled in 840 cities. The global average of sleep lost due to climate change rose from two hours annually in the 1970s to five hours by 2025.
Beyond fatigue, insufficient sleep affects mood, cognition, productivity, and health, linking to hypertension and diabetes. While air conditioning offers relief, it is not universally accessible, often tied to income levels, leaving many exposed to warm nights.
This study highlights a subtle yet significant impact of climate change: compromised sleep. As nighttime temperatures persistently rise, especially in tropical and economically challenged regions, achieving restful sleep may become increasingly elusive.
Original Story at colombiaone.com