New research published on Nature Ecology and Evolution claims that artificial light should be treated just like other kinds of pollution due to its ravaging effects on nature.
Humans are illuminating the world one bulb at a time, which accounts for a 2% increase in range and intensity each year. And according to a team of biologists from the University of Exeter, this is increasingly becoming problematic.
Their meta-analysis of 126 papers stitches together a bright, yet bleak picture of the world. The insects are not as good at pollinating stuff, trees bud earlier, seabirds meet their demise crashing onto lighthouses, and sea turtles wander off the wrong way thinking the blingy signs they saw are the dawning sun.
All the animal species under study showed reduced melatonin levels, which regulates circadian rhythm and is secreted in the dark. Both nocturnal (active at night, like owls) and diurnal (active during the day) animals showed signs of disturbances in their behavioral patterns. Rodents—which are mostly nocturnal—were active for a shorter window of time, birds began their songs and search for worms earlier in the day.
The silver lining
Not everything this 'excess of light' brings is dark. The scientists also reported that some species in certain locations actually derived benefit from the extra light. Some plants thrived while some species of bats surged in population. But all in all, the big picture is negative, especially for those insects that can't help bumping head-on towards lightbulbs and car headlights.
Lead author Kevin Gaston told MSN, “What stands out is how pervasive the effects are. The effects were found everywhere – microbes, invertebrates, animals, and plants. We need to start thinking about lighting in the way we think of other big systemic pressures like climate change.”
Gaston says there has been a surge in the number of studies conducted in the last 5-10 years, that is, largely due to the effects of this phenomenon becoming more pronounced and evident. Look at any comparative satellite picture of the Earth taken from a satellite and it's clear as day.
Another problematic change is the move away from sodium-vapor lamps easily recognizable from their soft amber light. Increasingly, they are getting swapped out for cheaper and more efficient white LEDs. This is detrimental from a biological perspective because while light has a wider spectrum, which in turn means more circadian rhythm disruption.
Gaston urged individuals and institutions to proceed with more caution saying: “At the moment, we have the attitude that lighting is something we chuck out there and don’t think about it very much. But we need to think in terms of using it only when we need it, where we need it and how we need it. It is another pollutant.”
“At the heart of this is a deep-rooted human need to light up the night. We are still in a sense afraid of the dark. The ability to turn the night-time into something like the daytime is something we have pursued far beyond the necessity of doing so.”