Should Artificial Light Be Treated Like Air Pollution?

Artificial light should be considered as serious a threat to the natural world as air pollution and global warming, according to a new study from a team of biologists at the University of Exeter. Writing in the scientific journal Nature Ecology and Evolution, the study found that the proliferation of artificial light continues to grow by around 2% per annum, leading the authors to draw parallels with climate change.

The paper, which evaluated the results of 126 previous studies on the topic, concluded that light pollution impacts upon all manner of flora and fauna. As well as negatively affecting their sleeping patterns, the light can also interfere with hormone levels, breeding habits and migratory routes. All of these factors combine to place further stress on animal populations that are already under threat from a number of anthropogenic activities and their consequences.

All animals affected

The natural world is an incredibly complex ecosystem, with the thermal physiology of birds and mammals intrinsically linked to their feeding, breeding, sleeping and migrating habits. The disruption caused by light pollution can play havoc with all of these elements, thus having a detrimental impact upon the survival of countless species.

For example, unnatural light levels can contribute to reduced pollination rates from insects, which in turn can upset the way in which both crops and wild plants grow. The study showed that both diurnal and nocturnal animals saw their behaviour affected by reduced levels of melatonin caused by the light pollution, with songbirds rising earlier and rodents sleeping for longer.

“What stands out is how pervasive the effects are. The effects were found everywhere – microbes, invertebrates, animals and plants,” explained Kevin Gaston, lead author on the research. “We need to start thinking about lighting in the way we think of other big systemic pressures like climate change.”

More concerted action required

Issues like air pollution have fully entered the mainstream consciousness of late, with sophisticated air quality monitoring equipment now commonplace across the globe and governments turning their attention onto how the problem can be addressed. Light pollution, on the other hand, flies comparatively under the radar. Despite the fact that the incidence of artificial light is growing by 2% every year, affecting all organisms on the planet, there is very little clamour for the issue to be taken as seriously as other environmental concerns.

Meanwhile, advances in technology are alleviating certain problems while exacerbating others. LED bulbs, for example, use less energy and are therefore kinder to the Earth in some respects, but the white light they emit has a wider spectrum than conventional amber bulbs. This means they can potentially affect more organisms on a greater scale than their predecessors.

However, addressing the light pollution crisis could hold some benefits. Unlike climate change, which requires significant investment into more sustainable forms of energy generation, all that’s needed to curb light pollution is a change in our mindsets. Switching off lights when not in use would be both environmentally and economically advantageous – but it will require a drastic change in the way humans think.