For the first time, scientists are linking climate change and sleep loss. Results of the study show that the increasing nighttime temperatures due to climate change causes sleep loss that will likely get worse in the years to come.
Climate Change And Sleep Loss
Even without a heat wave, we have seen the effects of rising temperatures in different parts of the globe. Now, a new research is showing that apart from other health impacts of climate change, sleep patterns are also affected by the increasing nighttime temperatures across the United States.
Using data from the Centers for Disease Control and Prevention Behavioral Risk Factor Surveillance Survey (BRFSS) from the years between 2002 and 2011, a random pool of respondents answered a survey regarding the perceived amount of insufficient sleep that they had over the last 30-day period.
The responses gathered from the CDC survey were then compared to daily temperature records from the National Centers for Environmental Information Global Historical Climatology Network while taking the respondents' location into consideration as well.
What they found was that for every 1-degree Celsius anomaly in nighttime temperature, there were almost 9 million nights of insufficient sleep per month, or a total of 110 million nights of insufficient sleep annually. What's more, they found that this is three times more likely during the summer compared to any other season of the year.
The nights of insufficient sleep likely happen because of how the unusually warm nighttime temperatures affect the circadian rhythm and thermoregulation that affects our ability to both fall and stay asleep.
Normally, a decrease in core body temperature prepares the body for sleep, and retains the optimal temperature until it rises again shortly before waking up. When temperatures are unusually high, the body is unable to reach a core body temperature that is optimal for a nighttime rest.
"Decreasing body temperature is one of the strongest signals to our brain to bring on sleep onset... Thus, when the ambient temperature is too high, the body cannot cool itself and therefore can't fall asleep," said Sara C. Mednick, coauthor of the study and sleep psychologist from the University of California at Riverside.
Who Are More Vulnerable To Insufficient Sleep?
Researchers of the study also looked into which members of the population are more susceptible to insufficient sleep due to increasing nighttime temperatures.
Their data suggests that members of the population that are more vulnerable to nighttime heat are the elderly individuals and those with an annual income below $50,000. These members of the population experience more severe sleep interruptions especially during warm summer nights.
2050 And 2099 Projections
Based on the current findings, researchers expect that this could only get worse as the temperatures continue to rise. Using 1981 to 2010 temperatures as the baseline, they project that people will experience up to six extra nights of insufficient sleep for every 100 individuals by the year 2050, and an extra 14 nights of insufficient sleep per 100 people by the year 2099.
Further, they project that states in the western and northern regions of the country are more susceptible to the rising temperatures, hence, would likely experience the most significant changes in rising temperatures.