New Delhi: Most of the studies which are focused on the impact of climate change on human life have analysed how extreme weather events affect economic and societal health outcomes on a broad scale. Climate change can also have a strong influence on fundamental daily human activities, which include a host of behavioural, psychological, and physiological outcomes that are essential to well-being.
Increasing ambient temperatures negatively impact human sleep around the globe, according to a study published May 20 in the journal One Earth.
How Is Climate Change Impacting The Sleep Patterns Of People?
In other words, climate change is causing people to sleep less. According to researchers from University of Copenhagen, Denmark, who led the study, the findings suggest that by the year 2099, suboptimal temperatures may erode 50 to 58 hours of sleep per person per year. The researchers also found that the temperature effect on sleep loss is substantially larger for residents from lower income countries as well as in older adults and females.
The fact that hot days increase deaths and hospitalisations and worsen human performance has long been known. However, the biological and behavioural mechanisms underlying the impacts have not been understood in depth. According to recent self-reported data from the United States, subjective sleep quality decreases during periods of hot weather, the study said. However, how temperature fluctuations may impact changes in objective sleep outcomes in people living across a variety of global climates has remained unclear, the authors noted in the study.
The researchers used anonymised global sleep data collected from accelerometer-based sleep-tracking wristbands. An accelerometer is an instrument used for measuring the acceleration of a moving or vibrating body. The global sleep data included seven million nightly sleep records from more than 47,000 adults across 68 countries spanning all continents except for Antarctica. The observations made by these wristbands had previously been found to align with independent measures of wakefulness and sleep, the study said.
What Happens On Very Warm Nights?
On very warm nights, sleep declines an average of just over 14 minutes, according to the study. Warm nights are those which are greater than 30 degrees Celsius or 86 degrees Fahrenheit. As temperatures increase, the likelihood of getting less than seven hours of sleep also increases.
Controlled studies previously conducted in sleep labs found that both humans and animals sleep worse when the room temperature is too hot or too cold. However, the new study was limited by how people act in the real world. People modify the temperature of their sleeping environment to be more comfortable, the researchers found.
Under normal living routines, people appear far better at adapting to colder outside temperatures than hotter conditions, according to the study authors. Also, people in developing countries seem to be more affected by these changes.
The greater prevalence of air conditioning in developed countries could play a role in this. However, the scientists could not definitively identify the reason because they did not have data on air conditioning access among subjects. The authors noted that since they uncovered compelling evidence that the impact of warming temperatures on sleep loss is unequal globally, new research must consider more vulnerable populations, especially those residing in the world's hottest and historically poorest regions, according to the study.
What Is Next?
The researchers from the University of Copenhagen will collaborate with global climate scientists, sleep researchers, and technology providers to extend the scope of global sleep and behavioural analyses to other populations and contexts. They will also study the impact of rising outdoor temperatures on sleep outcomes of populations living in hot climates, who may have limited access to air conditioning.