It’s no longer a metaphor when someone says that climate change keeps them awake at night. A new research paper reported that warm nights and sleep environments can lead to poor sleep in humans, especially in the elderly and low-income households. These findings indicate that the rapidly warming climate, as discussed in debates around the world, will lead to millions of hours of sleep loss in Americans by the year 2050. By the year 2099, it is estimated that this figure could be several hundred million nights of sleep loss on a yearly basis.
Nick Obradovich led the study. Dr. Obradovich did most of his research as a doctoral student at the University of California in San Diego. Inspiration came in the form of the massive heat wave that draped over San Diego in October 2015. He and many of his fellow students were having difficulties sleeping due to the heat, even with a window AC. Temperatures broke records that year, so tossing and turning at night was a normal occurrence. Students and professors alike walked the campus looking bedraggled and grumpy. This led to Dr. Obradovich’s interest in how climate change affects sleep.
The study was published in Science Advances. The research suggests the need for a large international study to identify the link between unusually warm nighttime temps and sleep loss, or changes in sleep patterns. This research serves as the original discovery of the relationship between sleep problems and climate change.
Dr. Obradovich reminds readers that there are many studies that have established sleep to be one of the most essential components of good health. Sleep loss and deprivation can lead to increased risk of disease, chronic illness, declining mental health, and impaired cognitive functioning. This new research suggests that ambient temperatures are not the only things that affect sleep, and that climate changes and warmer temperatures may be making the situation far worse.
Now a postdoctoral fellow at Harvard University’s Kennedy School of Government and at the Center for Marine Biodiversity and Conservation, Obradovich started the research with a sleep researcher and clinical psychology student from San Diego, as well as his dissertation advisor and social scientist.
Between 2002 and 2011, researchers collected data from 765,000 Americans after they responded to a public health survey entitled Behavioral Risk Factor Surveillance Survey. This was designed and administered by the Centers for Disease Control and Prevention. Information from this research showed them self-reported nights of poor sleep, and then they compared these findings to the daily temperatures from the National Centers for Environmental Information. The last step of the research was to combine the effects of higher temperatures on sleep quality using climate model projections.
Findings showed that an increase in nighttime temperature by 1 degree Celsius results in approximately three nights of poor sleep per 100 people each month. If, in one month, nighttime temperatures averaged 1 degree Celsius higher than previous years in the United States, that is equal to 9 million nights of sleep loss for the entire US population, which further translates to a staggering 110 million nights of poor sleep in a year.
Naturally, these negative effects are more problematic in the summer, with temperatures being nearly three times as high than any other season.
Additionally, these negative effects are not evenly spaced across demographic groups. Lower income households and those over the age of 65 were more likely to be severely affected. Older people had twice the negative effects than young adults. Lower income households reported effects three times more than people who made over $50,000 a year.
NASA Earth Exchange provided climate projections for 2050 and 2099, which led scientists to recognize a disturbing pattern for the future if climate change is not addressed. Continually rising temperatures could lead to six more nights of inadequate sleep per 100 people by the year 2050, and then an additional 14 nights per 100 people by the year 2099.
Dr. Obradovich notes that the United States is generally quite prosperous and temperate, so while there is not a whole lot of sleep data from other countries, it is safe to assume the pattern will be similar. It is likely that those in poorer and warmer climates have the same negative effects. In fact, it may even be worse. Further research is necessary to confirm this theory.