There is considerable concern amongst biologists that turning night into day has strong effects on the natural world and is yet another stressor on biodiversity. The fact that life has evolved, over millions of years, on a planet that has had periods of darkness for some of the time, might suggest that there would be consequences of the proliferation of Artificial Light at Night (ALAN). New LED lamps are a particular cause for concern as, their spectra tend have a large blue component, and blue light is a strong signal for daytime.
For example, there is evidence for melatonin suppression in vertebrates due to light:
For billions of years, all life has relied on Earth’s predictable rhythm of day and night. It’s encoded in the DNA of all plants and animals. Humans have radically disrupted this cycle by lighting up the night.
Plants and animals depend on Earth’s daily cycle of light and dark rhythm to govern life-sustaining behaviors such as reproduction, nourishment, sleep and protection from predators.
Scientific evidence suggests that artificial light at night has negative and deadly effects on many creatures including amphibians, birds, mammals, insects and plants.
Artificial Lights Disrupt the World’s Ecosystems
Nocturnal animals sleep during the day and are active at night. Light pollution radically alters their nighttime environment by turning night into day.
According to research scientist Christopher Kyba, for nocturnal animals, “the introduction of artificial light probably represents the most drastic change human beings have made to their environment.”
“Predators use light to hunt, and prey species use darkness as cover,” Kyba explains “Near cities, cloudy skies are now hundreds, or even thousands of times brighter than they were 200 years ago. We are only beginning to learn what a drastic effect this has had on nocturnal ecology.”
Glare from artificial lights can also impact wetland habitats that are home to amphibians such as frogs and toads, whose nighttime croaking is part of the breeding ritual. Artificial lights disrupt this nocturnal activity, interfering with reproduction and reducing populations.
Artificial Lights Can Lead Baby Sea turtles to their Demise
Sea turtles live in the ocean but hatch at night on the beach. Hatchlings find the sea by detecting the bright horizon over the ocean. Artificial lights draw them away from the ocean. In Florida alone, millions of hatchlings die this way every year.
Birds that migrate or hunt at night navigate by moonlight and starlight. Artificial light can cause them to wander off course and toward the dangerous nighttime landscapes of cities. Every year millions of birds die colliding with needlessly illuminated buildings and towers. Migratory birds depend on cues from properly timed seasonal schedules. Artificial lights can cause them to migrate too early or too late and miss ideal climate conditions for nesting, foraging and other behaviors.
Ecosystems: Everything is Connected
Many insects are drawn to light, but artificial lights can create a fatal attraction. Declining insect populations negatively impact all species that rely on insects for food or pollination. Some predators exploit this attraction to their advantage, affecting food webs in unanticipated ways.
And there is a database of other research findings in this context:
There are claims that brighter lighting greatly enhances public safety and these claims have been used to sell lighting but is this just a sales technique?
There is a consultation at the moment by the All Party Parliamentary Group (APPG) on Dark Skies Policy https://appgdarkskies.co.uk/dark-skies-consultation but it closes very shortly – Sunday 27th September 2020. Copied below from the website is further information:
Dark Skies Policy Consultation
The APPG for Dark Skies is seeking proposals and evidence from a range of stakeholders with expertise and experience in the subject of dark sky preservation and light pollution.
The purpose of this consultation is to collect information, to identify the main threats and challenges that the cause of dark sky preservation faces in the UK, and identify the most effective and actionable ways in which legislators and policy makers can seek to address these challenges – for example but not limited to the compliance and planning policy frameworks. It will explore the environmental, economic, energy and health consequences of light pollution.
The result of this consultation will be to produce the APPG’s first policy plan since being established in January this year. It will provide a basis for the focus of our campaigns, policy briefs and the language that our extensive group of Parliamentary members use.
Guidelines for making a submission:
- State clearly who the submission is from, i.e. whether from yourself in a personal capacity or sent on behalf of an organisation, for example the submission could be headed ‘Written evidence submitted by xxxxxx’
- Be concise – we recommend no more than 1,000 words in length
- Begin with an executive summary in bullet point form of the main points made in the submission
- Include a brief introduction about yourself/your organisation and your reason for submitting evidence
- Include any factual information you have to offer from which the APPG might be able to draw conclusions
- Identify any legal or quasi-legal frameworks your proposal would impact or modify
- Include any recommendations for action by the Government or others which you would like the APPG to consider.CLOSING DATE: Sunday 27th September
Please contact the APPG Coordinator Chris Cook (email@example.com) with any further questions.“
Does light pollution affect humans as well as other species?
I think this is still to be proven but my own experience over more than seven decades of life on this planet, is a great sadness at the gradual loss of an ability to see the stars at night. This has been exacerbated by the arrival, thanks to my City Council, of an LED lamp post right outside my home. It was probably placed there for good sustainable reasons but I now find it impossible to see the stars at night and, if I wake in the night, to be able to guess what time it might be, as it is always light now.
In another post on this site, I have written about “climate change grief” and I wonder if what I have described in the previous paragraph could be described as “light pollution grief”. I certainly believe that being able to see the stars at night gives us a sense of who we are as the inhabitants of a planet, which is just a small part of a diverse and beautiful universe. Can light pollution therefore lead to a loss of identity as an important species within this vast universe? And, going further, to a loss of responsibility for the benevolent stewardship of this planet or even to an impact on human mental health?
Related to this, as described in Chapter 3 of my book (Human Inventiveness and the Concepts of Freedom and Responsibility”), is the description of “space junk” currently circulating our planet and being added to on a regular basis.
It is now known that walking under trees can improve mental health – it is called “tree therapy”. Is it possible that standing and gazing up at the stars can be equally therapeutic?
Maybe this is important to me because five decades ago, I travelled by road from Darwin to Sydney, Australia and spent each night sleeping by the side of the road, under the starts. Is that why I miss them so much now? Certainly, I was gobsmacked when, returning to Australia 10 years ago, and staying at a small town with little light pollution, I felt like I was bathed in the Milky Way. It took my breath away. I had forgotten what I was missing.
Further information about light pollution can be found at: