The Harmful Effects of Light Pollution (credit: International Dark-Sky Association)

Light allows humans to see better at night, but did you know light is also a pollutant? Light pollution is a problem that many people aren't aware of. Light being emitted into the atmosphere has many negative impacts on Earth. Accumulating light can damage and modify the behavior of organisms and ecosystems.
 
There are several light sources that affect organisms. The International Dark-Sky Association (IDA) states that many light sources include building lighting, advertising, commercial properties, offices, factories, street lamps, and illuminated sporting venues. There is so much unnecessary light that it causes light trespass which is best defined as light being positioned in places where it is not intended or needed. A study by “World Atlas of Artificial Night Sky Brightness,” stated that the 99% population of the United States and Europe live under light polluted skies!
 
This extra light disturbs animals and plants, depending upon the natural darkness of night. Most life forms have cyclic behaviors that typically occur over the course of a 24-hour time span which is referred as a circadian rhythm. Plants, for example, are organisms that most often exhibit this cyclic behavior.  By adding artificial light to the night sky, this disrupts the ability of plants to determine when to prepare for winter dormancy, thus increasing the propensity for a more unexpected (or early onset of) death. Sunlight is more powerful, compared to moonlight and artificial light, but artificial light at night can be more powerful than moonlight which is why plants are often more affected by artificial light. This information originated from a study about plants in the “Berkshire Encyclopedia of Sustainability”.

Many types of living organisms are affected by light pollution as well. Nocturnal animals sleep during the day and are active at night. IDA found that light pollution alters their night-time environment by creating the illusion of it being day-time during night-time hours. Some animals that aren’t nocturnal need the darkness of night to survive. Sea turtle eggs are known to hatch at night on the beach. The hatchlings use the phosphorescence by microscopic sea life as a guide to get to the ocean. The phosphorescence appears as a green luminescent glow in the water. Anthropogenic light at night misleads the hatchlings away from the ocean, often resulting in their death. IDA states that in Florida, millions of hatchlings die this way every year.
 
You would think that because humans are the reason for this emitted light, that it wouldn’t affect them, right? According to the “Berkshire Encyclopedia of Sustainability”, light pollution disrupts sleep for humans as well. Humans produce hormones at night that help our bodies get ready for sleep. Night lighting disturbs a human’s ability to fall asleep which could result in health problems. If we can reduce the amount of emitted light at night, it would be beneficial to many different types of organisms living on planet Earth. (Credit: IDA, the Berkshire Encyclopedia of Sustainability, World Atlas of Artificial Night Sky Brightness)

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© 2018 Weather Forecaster Brittany Connelly