The advent of modern household conveniences like internal heating and electric lighting make it a whole lot easier to bear cold winters and dark nights, but the comfort we derive from these artificial manipulations of our immediate environment could be coming at a cost.
A new study says a pattern of disrupted seasonal rhythms is creating a disconnect with natural life processes and having a negative impact on human health, thanks to our over-reliance on artificial lighting and climate controls.
"The real take-home message is that seasonal rhythms are pervasive. Just like daily rhythms which tell us to sleep at night, a similar thing is happening seasonally," said Tyler Stevenson, a behavioural neurobiologist at the University of Aberdeen in Scotland, as reported by Sarah Knapton at The Telegraph.
"But over time these seasonal signals are dampening down. During the twentieth century our species has developed technologies that allow precise light and climate control over our living environments, and humans in developed societies now spend the vast majority of their lives in conditions that mimic 'summer-like' environments."
And it's not just a problem for people. The researchers say plants and animals worldwide are also affected, as environmental changes stemming from global warming are causing seasonal disruptions throughout the natural world.
But nowhere are the disruptions to natural biological rhythms more apparent than human society, thanks to our power and propensity to effectively redesign our living conditions to suit ourselves.
" Climate change is modifying annual rhythms to which numerous organisms have adapted, with potential consequences for industries relating to health, ecosystems and food security," the researchers write. "Disconcertingly, human lifestyles under artificial conditions of eternal summer provide the most extreme example for disconnect from natural seasons, making humans vulnerable to increased morbidity and mortality."
The seasonal impact on human health is wide-ranging, with researchers saying the time of year can affect everything from people's immunity levels to the impact of infectious and non-infectious diseases, plus suicide and homicide rates – and it even has an effect on the timing of battles in war scenarios.
Nonetheless, the authors say it's imperative that more work be done to try to understand better the comprehensive links between seasons and biological health.
"The collective nature of our work highlights that humans are not simply passive responders to seasonal climates," said Stevenson in a press release, "and the challenges we face now are in identifying how humans and other animals maintain seasonal time at a genetic level."
The findings are published in Proceedings of the Royal Society B.