INCREASING nighttime temperatures driven by climate change can harm human sleep, particularly for the poor and elderly, a new study has concluded.
Lead researcher Nick Obradovich, who actually conducted the study while enrolled in doctoral studies in political science at the University of California at San Diego explained in a statement, “Our study showed not only that ambient temperature can play a role in disrupting sleep but also that climate change might make the situation worse by driving up rates of sleep loss.”
According to the Harvard Medical School, sleep deprivation can lead to higher risk of chronic health problems such as hypertension, heart disease, and stroke. The university said that for people with hypertension, one night without enough sleep can cause elevated blood pressure all through the next day.
Obradovich and his colleagues surveyed 765,000 individuals across the US for the study, and compared their responses to temperature data from 2002 to 2011.
Their research showed that a one-degree Celsius increase in nighttime temperature translated to three nights of insufficient sleep per 100 individuals per month.
“To put that in perspective: If we had a single month of nightly temperatures averaging one degree Celsius higher than normal, that is equivalent to nine million more nights of insufficient sleep in a month across the population of the United States today, or 110 million extra nights of insufficient sleep annually,” the study said.
The negative effect of warmer nights—i.e., temperatures warmer than the normal seasonal average—was more acute in summer than any other season, the study added.
For older people, the effect is twice that of younger adults. And for lower-income people, it is three times worse than for people who are better off financially.
The study predicted warmer temperatures could cause six additional nights of insufficient sleep per 100 individuals by 2050, and approximately 14 extra nights per 100 by 2099 in the US, if climate change is not addressed.
“The US is relatively temperate and, in global terms, quite prosperous,” said Obradovich. “We don’t have sleep data from around the world, but assuming the pattern is similar, one can imagine that in places that are warmer or poorer or both, what we’d find could be even worse.”
The study was published this week in the US journal Science Advances.