Scientists have warned the numbers of sleepless nights people suffer is set to soar...
Rising temperatures will make it much more difficult to nod off - endangering millions of people's health.
The elderly and the poor will be worst hit, adding to the problems caused by climate change.
The researchers worked out the cost to sleep patterns across the US and said the findings could be applied to other temperate countries across the world.
Britain is already the most sleep deprived nation in Europe managing just six hours a night on average two hours less than the recommended amount.
The study published in Science Advances represents the largest real-world study to date to find a relationship between insufficient sleep and unusually warm night-time temperatures.
It's also the first to apply it to projected climate change.
Political scientist Dr Nick Obradovich said: “Sleep has been well-established by other researchers as a critical component of human health.
Too little sleep can make a person more susceptible to disease
"Too little sleep can make a person more susceptible to disease and chronic illness, and it can harm psychological well-being and cognitive functioning.
"What our study shows is not only ambient temperature can play a role in disrupting sleep but also climate change might make the situation worse by driving up rates of sleep loss."
Research has shown humans sleep better in a cold bedroom with the ideal temperature 17 degrees centigrade.
Dr Obradovich said if climate change is not addressed by 2050 could cost people in the US millions of additional nights of insufficient sleep per year.
By 2099, the figure could rise by several hundred million more nights of lost sleep annually.
Dr Obradovich was inspired by a heat wave that hit San Diego in October 2015.
He was having trouble sleeping. He also noticed fellow students at his California University campus were looking grumpy and bedraggled.
Global warming is predicted to cause an increase in the number of people struggling to sleep
Dr Obradovich, now at Harvard University in Boston looked at nine years of data from 765,000 Americans who responded to a public health survey between 2002 and 2011.
This enabled him to link self-reported nights of insufficient sleep to daily temperature data from the National Centres for Environmental Information. Then he combined the effects with climate model projections.
Increases in night-time temperature of one degree centigrade equated to three nights of insufficient sleep a month for every 100 individuals.
To put that in perspective a single month of this would be equivalent to 9 million more nights of insufficient sleep across the population or 110 million extra nights of insufficient sleep annually.
The bad effect of warmer nights is most acute in summer - almost three times worse than any other season.
Those whose income is below £38,870 or aged 65 and older are affected most severely. For older people, the effect is twice that of younger adults.
And for the lower-income group, it is three times worse than for people who are better off.
Using climate projections for 2050 and 2099 by NASA Earth Exchange, the study paints a bleak picture of the future.
Warmer temperatures could cause six additional nights of insufficient sleep per 100 individuals by 2050 - with this more than doubling to 14 by 2099.
The elderly and the poor are expected to be the worst hit by rising temperatures
Added Dr Obradovich: "The US is relatively temperate and, in global terms, quite prosperous.
"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."
A survey last year found adults in the UK are among the worst sleepers in the world.
More than a third (37 per cent) of Britons said they did not get the right amount of sleep.
A quarter listed getting a better night's sleep a priority, beaten only by wanting to lose weight.
17:01, Fri, May 26, 2017
original story HERE
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