Our Nights Are Getting Warmer Even Faster Than Our Days
And scientists think they know why
By Michael Harthorne,  Newser Staff
Posted Mar 11, 2016 4:48 PM CST
A new study explains why nights are getting hotter faster than days.   (AP Photo/Charlie Riedel)

(Newser) – Bad news for people who enjoy a chilly pillow while they sleep: Our nights are heating up much more quickly than our days. According to a press release from Uni Research, the number of very cold nights has dropped by 50% over the past 50 years, while the number of very cold days has dropped by only 25%. In the past, scientists have blamed the difference on local factors, such as precipitation and cloud cover. But a new study published last month in the International Journal of Climatology claims to have found the most important factor causing our rapidly warming nights: Nighttime temperatures are more sensitive to climate change.

The layer of air just above the ground is known as the planetary boundary layer. During the day, it's a few kilometers thick; but it contracts to only a few hundred meters at night. The study found nighttime temperatures are getting warmer than daytime temperatures because the radiation trapped by human carbon emissions has a smaller planetary boundary layer to heat at night. According to researchers, this is an important process to understand if we're going to be able to develop more accurate climate change predictions. (It seems Osama bin Laden wanted Americans to band together and fight climate change.)