In a world that starves for resources, pollution prospers in even the most unlikely of places. One unforeseen and sparsely researched threat is light pollution, which affects humans and the environment alike almost everywhere on Earth. Defined as the inappropriate or excessive use of artificial light, light pollution is an easily created issue with silent but deadly effects. Fortunately, research institutions across the world, including Trinity, are tackling the problem in new and innovative ways: Namely with the power of dark sky reserves.
Many of us have heard of the term circadian rhythm, which describes how the body uses an ‘internal clock’ to regulate and time bodily functions including sleep cycles, digestion and body temperature. The crucial part however is that the circadian rhythm takes its cues from environmental factors, including light. It’s unsurprising then that humans living in areas which are essentially lit up 24/7, namely urban areas, experience disruption to numerous essential bodily functions which leads to poor physical and mental health, the most obvious effect being insomnia.
On top of this, studies show that the effects of light pollution are even more detrimental for animals and the environment. Timing is crucial to the animal kingdom, and due to light pollution activities such as feeding, predation, migration and even reproduction are affected by artificial light. Nocturnal animals are among the worst affected.
Studies in Ireland, including those done by Trinity researchers, show that animals such as bats, badgers, red foxes, salmon, sea birds and even spiders suffer serious disruptions across many stages of their life cycles in both rural and urban areas. Plants too are affected and disruptions to photosynthesis mean that less carbon dioxide is taken up and greater damage to the ozone layer is therefore caused. On top of environmental concerns, there’s also the millions of euro and tens of tons of carbon dioxide wasted on excess lighting per year, both publicly and domestically. Another effect on society is the visibility, or rather invisibility, of the stars in our night sky. Many across cities such as Dublin cannot see the Milky Way from their gardens and also struggled to partake in the recent excitement when the Northern Lights (Aurora Borealis) was visible for the rest of the country.
It’s clear that something needs to be done to preserve our areas untouched by light pollution and to fight for change in affected areas. This is exactly what Dark Sky Ireland (DSI) does. As a branch of Dark Sky International, DSI aims to encourage policy development and public interaction centred around preserving areas of Ireland’s nightscape. They have done this by establishing three dark sky reserves across Ireland, one in Kerry, one in Mayo and one in Tyrone. DSI defines a dark sky reserve as “a land that possesses exceptional or distinguished quality of starry nights and a nocturnal environment that is specifically protected for its scientific, natural, educational, cultural heritage and/or public enjoyment”. Two of the reserves have been awarded Gold Status, Kerry in 2014 and Mayo in 2016.
The organisation’s remarkable work has not been easy, as Ireland has no legislation governing light pollution as it does for other forms of pollution. However, using the research of scientists including DSI’s own chairperson Professor Brian Espey, they have brought together stakeholders and citizen scientists alike to fight for the areas’ right to protection. Espey is also an astrophysics researcher at Trinity and is Ireland’s leading expert on light pollution.
DSI has more plans to further influence policy, increase outreach and earn more funding, all to develop more long term sustainability for Ireland’s dark skies. Cities and other urban landscapes, however, are not as easy to restore as national parks are. Artificial light is a crucial part of urban living for businesses, transport services and housing. Street lights, which are often the most reported source of light pollution, are prioritised over pollution concerns by urban planners and citizens alike as a safety feature to prevent crime, particularly violence, at night. One 2019 paper by Professor Espey suggests changing from traditional bulbs to light-emitting diode (LED) lighting in public areas as they emit a colour with potentially less impact on human health. These warmer colours along with dimming the lights and cutting down on unnecessary ones in general are expected to reduce energy costs and gas emissions. The paper also references a study in the UK which found that similar changes in England and Wales caused no significant change in crime or traffic collisions. Citizens and business owners can also do their part by cutting down on any unnecessary artificial outdoor lighting at night and encourage others to do so too.
Much more work is needed to create and integrate plans to mitigate the effects of light pollution in a way that complements city living. This highlights the importance of communication between scientists and policy makers to come up with solutions to balance the interests of all members of society.
