How Does Light Pollution Affect the Environment?

When Thomas Edison patented the first commercially successfully light bulb in 1879, it’s certain that humanity took a huge step forward. No longer would people be restrained from activity or endeavour by the rising and falling of the sun; the era of artificial light had begun.

It’s probably just as certain that when pioneering the bulb, Edison never considered the environmental implications that his invention might have. More than 135 years on, artificial light is becoming more widespread and brighter than ever – but how does this affect our planet?

Growing ever brighter

A new study from a German research centre has analysed images from a new NASA instrument known as VIRUS DNB (Visible Infrared Radiometer Suite Day-Night Band) and found that the Earth is now more brightly lit than ever before.

In the four years between 2012 and 2016, the amount of the planet’s surface illuminated by artificial light grew by 2% per year. If that growth continues at the same pace, we will be emitting more than double the amount of light in 2050 as we were in 2012.

The news comes as something of a shock as much of the western world has now transitioned to LEDs and other energy-efficient bulbs. Despite this measure, the use of light in urban areas in the USA stayed the same, while in places like the UK and Germany, it actually grew. Much of the developing world (including many parts of Africa, Asia and South America) also showed dramatic growths in light emittance; indeed, the only places which demonstrated decline were war-torn countries such as Syria and Yemen.

The only explanation for the boom in artificial light (especially in developed countries) is that humans are now using more than before. While this is beneficial for improving visibility at night time, it may not always be necessary and could have a surprisingly large impact on the environment.

The price of progress

To understand exactly how artificial light pollution affects the natural world involves analysis of complex environmental matrices and their interrelationship with one another. For example, it can throw the routine of nocturnal animals and insects into confusion and disarray, thus disrupting their feeding, breeding and sleeping habits.

Additionally, the migratory routes of certain birds can be upset by the enhanced lightening of our skies, which in turn has a knock-on effect on many plants which rely on cross-pollination to thrive. It’s just not wild fauna that is affected, either; many crops depend upon birds and insects to help them spread seeds and prosper.

At the extreme end of the spectrum, light pollution can even affect seasonal patterns. Last year, it was found that light pollution caused spring to come a full week earlier than normal, having unpredictable and potentially irreversible effects on the flora and fauna of our planet.

On a merely human level, increased light pollution has been linked with a whole host of health complaints, including headaches, migraines, anxiety, stress and fatigue. Perhaps most concerning of all, the lightening of the skies could disrupt our sleeping patterns and cause us to miss out on the rest that is so vital to our body’s health and upkeep.