For most of human history, when the sun set and night descended it meant that it was time to sleep. But, as our earliest ancestors learned to create fire, they found they could extend their days beyond the confines of daylight--and it was in these flame-lit hours, after the hunts had ended and labor halted, that men and women first began to craft their stories and culture around a fire their evening repose. The ancient Greeks were the first to use street lamps: burning oil to light obstacles on a path or to keep danger at bay. Artificial lighting has come a long way since then, so much so that nowadays many city dwellers can spend years without seeing natural darkness. But, for all the comfort and security we draw from our nighttime lights, new literature suggests that it may be harming species that only know the sun and moon.Shedding Light Onto the Problem
According to a soon to be released book, Before the Fireflies Are Gone (translated from Portuguese), all this artificial lighting that we've become so dependent on has an adverse effects on plants, insects, and even ourselves. The book's author, Alessandro Barghini, warns that streetlamps and floodlights may be taking its toll on organisms that depend upon the darkness of night.
The lighting is responsible for generating pollution astronomical and excess carbon dioxide emitted through the production of electricity, but the impact of light on biodiversity is much greater.
Night-Lights Harm Fireflies, Birds, Plants...and Us
Barghini, who based his doctoral research on the effects artificial lighting, titled his book after observing declines in firefly populations. Female fireflies produce their trademark light to attract males only when ambient lighting is below that of a full moon. With lighting systems in developed areas usually exceeding that brightness, female fireflies are not attracting males--threatening the future of the species
According to a report in Ambiente Brasil, Barghini also notes that birds may be the most poignant indicator of artificial lighting disrupting natural cycles.
Some birds in cities sing all night due to the presence of street lighting
The researcher suggests that the wavelengths in certain light bulbs, often favoring the blue radiance, may be impacting human metabolism. Common white LED lights, he said, are introducing an unnatural amount of blue radiance which could be responsible for altering metabolic reactions and disrupting sleep.
Plants, too, are subject to the potentially hazardous effects of artificial lighting. According to Barghini, "depending on the wavelength, the lamps can both induce and inhibit flowering." Some plants have sensitive circadian rhythms and could be confusing artificial lighting for daylight.