When we think about the environmental effects of climate change, most of us think of skies filled with smoke from wildfires, hurricanes battering the coasts, a rising sea level, flooding, and other seemingly apocalyptic scenes. When we think about the human impacts of climate change, we think of global refugees fleeing deadly weather events or disappearing coastlines, but also of increased stress and anxiety about a collective uncertain future.
What we might think about less is the way climate change impacts us in smaller, daily ways. Perhaps one of the most overlooked impacts is the toll that climate change takes on our sleep. And it’s hardly insignificant, whether you live in a region impacted by wildfires, flooding, rising seas, and hurricanes or not
In recent years, several climate-concerned sleep researchers have begun studying and reviewing the impacts of climate change on sleep, from nighttime temperature to diminished sleep time.
“I’m mostly a clinical sleep specialist myself. This is more of a labor of love,” says Dr. Daniel Rifkin of his climate change sleep research. Rifkin is a medical director at the Sleep Medicine Centers of Western New York and a clinical assistant professor of neurology at the State University of New York at Buffalo. His research looked at the relationship of sleep to climate change, from temperature changes, weather events, and extreme disasters.
“We know that climate change is going to have this tremendous effect on weather, and extreme weather can affect sleep,” Rifkin says of his work.
“I’m a full believer that our reliance on fossil fuels has fueled the change in our climate,” he says. “I did this paper to spark interest in my younger sleep colleagues because these issues are primarily going to be tackled by sleep researchers, so that’s why I [got it published] into a sleep journal.”
How climate change is slowly disrupting your sleep
Sleep, it turns out, is a central and universal place to witness the consequences of climate change. From temperatures that make it too hot to sleep to the worry and existential dread that keep people up at night, climate change leads to sleep disruption. And consistently getting insufficient sleep can result in diminished health and wellness, like chronic diseases and worsening mental health.
One of the most glaring takeaways to emerge from climate-focused sleep research in recent years is how it lines up with other climate change research regarding who will suffer first and the most from a warming climate — largely those who are older, lower-income, and living in less developed areas of the world, many of whom are already experiencing those consequences today.
“Things like civil conflicts, mass migration, and democratic institutions failing — these are all extreme and costly outcomes [of climate change],” explains Dr. Nick Obradovich, a senior research scientist and principal investigator at the Max Planck Institute for Human Development within the Center for Humans and Machines at MIT who led the inaugural study into nighttime temperature, sleep, and climate change.
“However, most people most of the time aren’t going to be exposed to mass migration or democratic collapse, at least over the coming decades according to most of our projections,” he says.
While climate change events will impact everyone to varying degrees and at different points of their life, it’s clear the most vulnerable around the globe — seniors, children, displaced communities, low-income communities, and those with chronic health conditions — will be the first to suffer the health consequences. For the rest of the population, even those who may not live in a place engulfed by wildfires or plagued by record-setting heat waves, there will be the day-to-day consequences of witnessing how the Earth is changing.
In fact, Obradovich has surveyed it.
By coupling data from 765,000 respondents in the United States from 2002 to 2011 with warming nighttime temperatures, Obradovich found that increases in nighttime temperatures amplify self-reported nights of insufficient sleep — and that the effects are larger in the summer and disproportionately experienced by low-income and elderly populations.
The scientific data behind climate change and sleep
While it was previously difficult to conclusively determine the impact of climate change on sleep, a new global study published last month found that rising temperatures are, in fact, worsening our sleep.
For this study, published in the journal One Earth, in May of 2022, Obradovich teamed up with Kelton Minor, a P.h.D student at the University of Copenhagen’s Center for Social Data Science. Linking over 10 billion sleep measurements from wristbands worn by people in 68 countries with local weather and climate data, the research team found startling results: Warmer-than-average nights worsened human sleep globally, but unequally.
The team found that not only does it become more likely that people will sleep less than seven hours as temperatures rise, but the effect was twice as pronounced among the elderly and females, and three times greater for residents of lower-income countries. “One of the most fascinating pieces of the study is that we found evidence that people who are already living in warmer climates, those who we might expect to be better acclimated to warmer climates, actually experienced greater sleep erosion per degree of temperature rise,” Minor explains. This, he says, suggests a limited ability for humans to adapt their sleep to a warming climate.
How worsening air quality impacts sleep
Air quality is another area that’s rapidly impacting our sleep quality and overall health.
“I live in California and we have wildfires every year,” explains Dr. Yishan Xu, a sleep specialist and licensed clinical psychologist. “When the fires are going on and the air quality gets worse, a lot of people’s sleep gets worse. Some people who I’ve already treated, and their sleep got better, once the air got worse and they [couldn’t] get enough sunlight and outdoor activity [to the point that] they worried a lot about their physical health, [their sleep regressed].”
As climate change fuels more and bigger wildfires from California to Australia, smoke-filled skies pose a threat to more than just air quality itself. “Some of it is the darkness,” Xu explains. “When it’s cloudy, it sometimes makes people more sad and makes them more emotional at night. We tend to ruminate at night a lot.”
The further lack of contrast between the light of day and dark of night can also disrupt our circadian rhythms, our internal biological clocks, and mess up the cues that signal our bodies that it’s time to wake up or time to go to bed.
Climate change anxiety can also weigh on our mental health
“One of the things that’s a really important component of sound mental health is the ability to get good sleep at night,” Obradovich says. Temperature changes, environmental security, and extreme weather conditions may keep you tossing and turning. “If you can’t sleep at night because it’s unusually warm… that has effects on your next day goes — your productivity, interaction with people, your immune system, all of that can then accumulate over time to larger outcomes in terms of mental health.”
Then there’s the combination of anticipatory anxiety and existential dread from climate change that can creep in at night, which can also lead to subsequent nights of insomnia. Even if you are not directly impacted by climate change, the existential stress has a tendency to hover over anyone concerned with the future, from the viability of the environment and their ability to live in it to their children’s and grandchildren’s abilities to live in it.
“There’s just way more stress and uncertainty, especially for people who have less resources,” explains Dr. Jade Wu, a behavioral sleep medicine specialist and researcher at Duke University School of Medicine.
New reports from the Environmental Protection Agency found that Black, Indigenous, and Latino Americans will be disproportionately impacted by climate change. These populations will be more likely to lose out on more work, be diagnosed with asthma, and face higher mortality rates due to the increase in heat.
“When the temperature is really high” — as it has been across the United States this summer, with July clocking in as the hottest month on record — “or when they don’t have access to things like cooling or fresh food, or certainty about where they’re going to be staying, that kind of stress can seep over into every aspect of their health including their sleep,” says Wu.
Even those who do have more resources still may not be able to control their environments, especially during their sleep, which can lead to disrupted sleep or nighttime heat exhaustion. “Large segments of the U.S. and the rest of the world don’t have adequate air conditioning at night,” Obradovich points out.
“There are huge segments of the human population that are not able to just buy, install, and afford to run air conditioning. And even for those who can afford it, the current carbon intensity of our energy system means that it’s contributing to global warming.”
Then there are natural disasters, like hurricanes, that knock out power and take away the ability for people to sleep securely, whether that’s through a lack of air conditioning or evacuation to a location where they can’t control their sleep environment.
In addition to calling for more research on the impacts climate change has on sleep, Rifkin hopes to see quality sleep recognized as an important consideration for all applications in the future.
“One of the big [effects of climate change] is going to be displaced people. I think it is really important to make sure that sleep environments are taken into account in the places where these people are going to wind up,” he says, from refugee camps to resettlements around the world.
In the meantime, there are still small things you can do to break the cycle of stress and dread, and lessen their impact on your mental health so you can focus on sleep. Xu recommends experimenting and discovering wind-down routines that work and, in instances of stress, to consider extending those periods of relaxation. A wind-down routine, Xu says, can be anything you find relaxing or soothing, from cleaning or going for a short walk to reading or a nighttime skin care routine.
“Some people do gentle stretching or yoga. A lot of Chinese clients use hot water on their feet. Some people use essential oils or drink herbal tea,” she says, adding that there are always sleep specialists available to help.
However, if your feelings of dread stem from feeling out of control, finding ways to make an impact could ward off feelings of helplessness. You can set long-term goals such as waste reduction and building new lifestyle habits that offset carbon emissions. For more immediate action, look up how to donate to displaced communities and individuals, and don't forget to emotionally check-in with close friends and family who may have loved ones in affected areas.
