Losing Sleep Over Climate Change: The Hidden Impact of Rising Temperatures

BY LIZZIE FISHER

Polluters might claim they don’t “lose sleep” over their actions, but in reality, they—along with millions of others around the world—do. A study published in One Earth, examined sleep patterns of more than 47,000 individuals across 68 countries over six months. Using wristband data, researchers found that rising ambient temperatures significantly disrupt sleep. The most severe effects were observed in vulnerable populations—particularly individuals from lower-income countries, people over 65, and women.¹ The National Sleep Foundation recommends that adults sleep seven to nine hours per night. However, research shows that when nighttime temperatures exceed 25°C (77°F), people are 3.5% more likely to sleep less than seven hours.² Given that sleep is essential for health and one-third of adults already experience sleep issues, this presents a serious concern.³ Sleep affects nearly every aspect of well-being, both physiological and psychological.

Temperature regulation plays a crucial role in initiating the sleep cycle. Before falling asleep, the body naturally cools itself by dilating blood vessels near the skin’s surface. Once body temperature drops sufficiently, individuals can sleep through the night, with their temperatures rising naturally as they wake up. Climate change is disrupting this process. Warmer nights interfere with circadian thermoregulation, making it harder for people to fall and stay asleep.³ As climate change intensifies, these disruptions will only become more frequent and severe.

The One Earth study highlights how climate change-induced sleep loss disproportionately impacts women, low-income individuals, and older adults.¹ Notably, women are more vulnerable to sleep loss than men, a disparity that may stem from physiological differences in temperature regulation. Women’s bodies begin cooling earlier in the evening, meaning women are disproportionately affected by higher ambient temperatures at bedtime, which can make it harder to fall asleep. Additionally, women tend to have a thicker layer of subcutaneous fat—the fat stored just beneath the skin—which, while beneficial for heat retention in colder conditions, can also hinder the body’s ability to release excess heat at night, further disrupting sleep.¹

Individuals in lower-income countries experience nearly three times the sleep disruption of those in wealthier nations, largely due to limited access to cooling technologies, heat-resilient infrastructure, and other resources that could mitigate nighttime temperature discomfort.¹ Meanwhile, older adults experience nearly twice the level of sleep disruption compared to younger individuals. Researchers found that “the effect of a 1°C increase in minimum temperature among the elderly is over twice the effect observed in other age groups.”¹ This heightened vulnerability is likely due to age-related declines in thermoregulation, along with the fact that older adults tend to sleep earlier and for shorter durations, making them more susceptible to warming nighttime temperatures.¹ As a result, they are especially at risk for climate-related sleep disturbances, highlighting the urgent need for targeted interventions.

Beyond temperature, air pollution also negatively impacts sleep. Studies suggest that exposure to air pollution can contribute to Sleep-Disordered Breathing (SDB) and obstructive sleep apnea (OSA).³ One key factor is particulate matter, which is a harmful component of air pollution that causes inflammation in the lungs, nasal passages, and upper respiratory tract. As a result, poor air quality can lead to increased nighttime awakenings, reduced sleep efficiency, and long-term respiratory issues that make restorative sleep even harder to achieve.³

While one might assume that the human body will adapt to these changing climate conditions, research findings contradict this notion. The One Earth study found that individuals living in already warm climates lose even more sleep per degree of temperature increase compared to those in cooler environments.² Rather than building resilience, people in hotter regions become increasingly vulnerable to sleep loss as temperatures rise. This underscores the urgency of addressing climate change rather than assuming adaptation will happen naturally.

While preventing further climate change and reducing nighttime heat should be global priorities, short-term solutions are also necessary. The One Earth study suggests that increased access to cooling interventions, such as air conditioning, may improve sleep quality.¹ However, access to both standard air conditioning and renewable energy remains highly unequal, particularly for low-income communities in the U.S. and globally. Many economically disadvantaged households face the “heat or eat” dilemma, where they must choose between affording food or paying the energy bills to cool their homes during extreme heat.⁴ However, widespread use of these technologies can contribute to the very problem they seek to solve by increasing energy consumption and greenhouse gas emissions.³ Instead, sustainable solutions—such as implementing energy-efficient cooling systems and transitioning to renewable energy sources—must be prioritized and made accessible to all.

Sleep is fundamental to human health, productivity, and overall well-being. If we ignore the connection between climate change and sleep loss, the problem will only worsen. While there is no simple fix, taking action can make a meaningful difference. So, the next time you find yourself tossing and turning on a hot night, struggling to drift off, remember—it’s not just you. This global problem will not disappear on its own, but if we make smarter choices and invest in sustainable solutions, we can build a cooler, healthier future—one where a good night’s sleep isn’t a luxury, and the sweet dreams of quality sleep come a little easier for everyone.

Lizzie Fisher is a first-year in Saybrook College.

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References

1. Minor, K., Bjerre-Nielsen, A., Jonasdottir, S. S., Lehmann, S. & Obradovich, N. Rising temperatures erode human sleep globally. One Earth 5, 534–549 (2022).
2. Marples, M. Expect to lose up to 58 hours of sleep a year by 2099. Here’s why. CNN https://www.cnn.com/2022/05/24/health/sleep-loss-global-warming-study-wellness/index.html (2022).
3. Ayta, S. The Effect of Air Pollution and Climate Change on Sleep. Noro Psikiyatri Arsivi 61, 73–76 (2024).
4. Hernández, D. Energy Insecurity: A Framework for Understanding Energy, the Built Environment, and Health Among Vulnerable Populations in the Context of Climate Change. Am. J. Public Health 103, e32–e34 (2013).