The impacts of climate change are far-reaching: from changing weather patterns to more natural disasters (think: storms, flooding, wildfires, etc.), the effects of rising temperatures are practically everywhere. And now, earth’s warming is affecting yet another part of our lives: bedtime. According to a new study, sleep loss is tied to global climate change because temperature increases make it more difficult to sleep.
Researchers at the University of Copenhagen tracked sleeping adults in 68 different countries and found that warmer nights pushed bedtimes later and caused people to wake up earlier. Even sleepers that lived in places with cooler climates were impacted.
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When temperatures passed 30 degrees Celsius, sleep declined an average of 14 minutes. And sleepy adults who need seven hours of sleep or more are out of luck if they live in an area where temperatures exceeded 25 degrees Celsius, as that increased the chances of getting less than seven hours of shut-eye.
“Our bodies are highly adapted to maintain a stable core body temperature, something that our lives depend on,” the study’s lead author Kelton Minor said in a press release. “Yet every night they do something remarkable without most of us consciously knowing — they shed heat from our core into the surrounding environment by dilating our blood vessels and increasing blood flow to our hands and feet.” However, humans cannot complete this process if the place where we are sleeping is not cooler than we are.
Related: Poor sleep linked to mental illness, large-scale study says.
Other factors such as your age, sex and class factor into your susceptibility to sleep loss. Adults over the age of 70 lost approximately 30 minutes instead of 15 minutes of sleep as others in similar climates. And if you’re a woman, you may be more sensitive to the heat, as women in the study lost about 25 per cent more sleep. If you are a citizen of a lower- or middle-income country, you’re likely to have your sleep impacted nearly three times as much as people who reside in high-income nations.
“In order to make informed climate policy decisions moving forward, we need to better account for the full spectrum of plausible future climate impacts extending from today’s societal greenhouse gas emissions choices,” Minor said.
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