Humans are going to be a lot sleepier in the future if a new study about the impact of global warming is on the mark.
In fact, by the end of the century, folks could be losing a total of two weeks of sleep annually because of rising temperatures, the Danish-led paper shows. While the impact is worse in the future, scientists say high temps are already unsettling our slumber.
Researchers collected data from more than 47,000 people living in 68 countries in what they call a planet-scale natural experiment. Participants wore sleep-tracking wristbands for two years starting in 2015. Then their sleep patterns were matched with weather and climate information.
The investigation notes temperatures are rising globally, with the greatest increase seen at night, when most of us are dropping head to pillow. The work confirmed that higher-than-normal temperatures eroded sleep quality and duration. The odds of getting less than seven hours sleep in one stretch increased with the heat.
That is bad news for our health. Sleep loss can lead to diminished immune function and cardiovascular mortality, among other effects.
Scientists found sleep loss is twice as high in the elderly compared with younger people. And the impact was three times higher for those living in low-income nations, compared with richer countries where air-conditioning is prevalent along with stable electric grids.
They note that humans just don’t adapt well to higher temperatures. Generally, we tend to fall asleep later and wake up earlier, tossing and turning as we sweat on our journey to dreamland.
Perhaps come bedtime, we should start counting penguins instead of sheep.