Can Climate Change Factor Into Sleep Disorders Like Narcolepsy?

We have now endured several years of protracted wildfire seasons. Recently, high-temperature records across the globe were broken. The volatile shift in hurricane ranges, length of seasons, and rising wind and rain levels aren't lost on us.^1-4

How will we sleep through climate change? With reports of humans being globally sleep-deprived:⁵

• What will happen if climate conditions worsen?
• Who should be the most concerned?

The link between global climate and sleep

All living things bear a relationship with the planet that is distinctly linked to its light-dark cycles. For humans, circadian rhythms – which regulate sleep and a host of other functions in the body – are tightly entrained to the seasons and patterns of day and night.

It is all about the light. Our wakefulness depends upon our access to daylight, and our sleepiness depends upon our ability to find and sustain darkness.

However, other biological factors influence our circadian rhythms. These factors are further influenced by potential climate change problems: rising temperature, air pollution, and problems with displacement.

Rising temperatures and sleep

Temperature – of both your body’s core and skin – informs your relationship to sleep.

During the day when you are awake, your core body temperature runs high, while your skin temperature runs lower, thanks to sweating. This leads to maximum alertness and wakefulness. Meanwhile, at nighttime, your core body temperature should cool off, while your skin temperature naturally increases. This creates optimal conditions for sleep.⁶

These are circadian markers of sleep. Other circadian markers rely on the amount of available light, the timing of the change from light to dark (and vice versa), activity levels depending upon time of day, and the timing of meals.⁷

In a climate change scenario, circadian markers may be disrupted when environmental temperatures run to extremes.⁸

For instance, a protracted heatwave will likely interfere with your sleep. This means you will need to seek out space-cooling methods or cool drinks at bedtime in order to maintain a lower body temperature. This, of course, pertains to anyone trying to sleep through a heatwave even without the added concern of climate change.

Global warming and narcolepsy

However, if rising temperatures become the rule rather than the exception – a theory offered by climate change scientists – then there is reason for concern. People with certain sleep disorders, such as narcolepsy, may find these challenges even more difficult – if not impossible – to overcome.⁹

Researchers studying both core and skin temperatures in people with narcolepsy and cataplexy have known for a while that the brains of these people lack adequate supplies of a specific sleep-wake regulating substance. This substance is known as hypocretin or orexin.¹⁰

Because of this, people with narcolepsy and cataplexy have dramatic increases in daytime skin and core body temperature.¹⁰

This known deficit in hypocretin may be a chief reason why people with narcolepsy and cataplexy find themselves so much sleepier during the day. If nighttime temperatures remain on the rise, as some research continues to suggest, this could lead to greater challenges for these people.^7,9

Pollution and evacuation: 2 other natural disaster outcomes that impact sleep

Other environmental concerns linked to climate change may leave a mark on sleep quality in the years to come. Wildfires, hurricanes, earthquakes, and other natural disasters demand evacuation and large-scale crisis intervention.

For people with sleep-breathing disorders like obstructive sleep apnea (OSA), air quality problems caused by persistent wildfire smoke can impact sleep, possibly worsening the situation.^11,12

More broadly, people facing acute anxiety during all natural disasters may experience sleep deprivation and debt, with its predicted anxiety – and maybe even PTSD – sometimes persisting and becoming chronic over an extended period of time following the initial events. ^13,14

Should people with sleep disorders be concerned?

It seems practical that people with sleep disorders plan ahead in anticipation of risks posed by climate change.

• Narcolepsy – Treatment that both improves hypocretin and helps maintain proper body and skin temperature according to time of day should offset circadian disruptions caused by climate change.
• OSA – CPAP users may need to invest in portable power supplies for their equipment in the event of evacuation. They may also want to invest in better air filtration for their homes (beyond the CPAP filters) to help combat air pollution caused by wildfires.
• Insomnia – Forms of sleeplessness linked to anxiety – such as current problems with COVID-somnia – demand better treatments to restore sleep under duress, such as evacuation displacement or during waves of extreme temperatures.

Meanwhile, scientists continue to look at how the future of our climate may shape our collective ability to sleep. Their goal? To create solutions that protect human sleep through the next century and beyond.

As sleep medicine researcher and expert Daniel Rifkin suggests, “Sleep health should be included as an integral part of any climate resilient system.”¹³