As she struggles to see the night sky, Ellina Webb looks into the effect of light pollution on the world around us and why turning off your lights at night won’t just save you money but will also reduce your impact on the environment .

With Jupiter and Venus aligning recently, the internet has been buzzing with astrological theories as to how this phenomenon will affect your health, fortune, career and love life. But for those of us who are merely fascinated in the science behind the astral movements above us, this alignment was one of the many great sights of the night sky. Being born in the 80s, I am one of the many generations that remember Patrick Moore’s The Sky at Night which ran between 1957 and 2013, and like many viewers it sparked an interest into stars, planets and beyond. However, my interest never reached a ‘buying-of-telescope’ type of level and that’s mainly because, living in a light polluted town meant seeing the sights were difficult. Light pollution is where the presence of artificial light becomes unnecessary, affecting people and wildlife and detracting from the countryside and the night sky. Sadly, it’s not a common term that people have come across, especially those my age and the generations below me who spend hours staring at blue-lit screens of smart devices well beyond bedtime. Being born in the technological age, we’re used to seeing a constant glow over the horizon and with 85% of the population living in urban areas and 90% of the population affected by ‘sky glow’; that’s potentially a lot of young people who may not have ever seen the stars. But what is the effect of light pollution on our environment and how can we reduce the impact?

According to studies, due to light pollution 60% of Europeans and 80% of North Americans can no longer see the Milky Way at night.

Light pollution, people and wildlife Light pollution can affect humans in a number of ways, for example, sleep patterns can be affected as the natural light-dark cycle of day and night is compromised. In fact most of us who live in residential areas will rarely experience a truly dark night. According to darksky.org research suggests that artificial light effecting sleep patterns can increase the risk of obesity, depression, sleep disorders, diabetes, breast cancer and more – and FYI, exposure to blue light at night is worse, which is why it’s best to switch off your devices before bed. In fact, inside and outside your home it is recommended you look for warm light sources with a colour temperature of 3000k or lower so you do not affect the sleep patterns of yourself and your neighbours. With regards to wildlife, moths are one of animals most affected by light pollution because their attraction to light makes them more vulnerable to predators as well as traffic. Artificial light also affects bats, frogs and insects like glow worms – all of which are common in urban gardens and this is why your outside lighting may need some adjusting.

Increase of light pollution at Christmas I don’t mean to put a downer on the Christmas festivities (after all, I am that person who plays Christmas songs at the beginning of November) but according to this article on American site News Republic, “Christmas lights are ruining your health and the environment” (much in the same way I described above). Could that be the reason why we all struggle to get to sleep on Christmas Eve? Of course in terms of the requirement of luminosity from Christmas/holiday lights, we all know they are impractical and purely decorative, but there are some things we can do to ensure the Christmas spirit is kept high, the light pollution is kept low and our wildlife and sleeping patterns aren’t too disrupted:

A low light-polluted Christmas – Use LED fairy lights which are more flexible in how they direct light

– An even better solution is to use solar powered LED fairy lights

– OR even better yet use solar powered LED fairy lights with a low colour temperature

– Ensure your lighting is on a timer so it switches off after bedtime and stays off until dusk

– Keep Christmas displays minimal – if only to help with money saving

Light pollution and the night sky Light pollution affects the night sky because light is often directed above the horizontal into the sky, creating sky glow – which is why we are often unable to clearly see the stars. According to the British Astronomical Association sky glow is caused by poorly aimed streetlights and floodlights and vastly over-powered household security lights and sports lights. In 1989 the British Astronomical Association and International Dark-Sky Association started an anti-light pollution campaign called The Commission for Dark Skies. The aim is to improve lighting, advise local people and combat sky glow. Their work, along with the House of Commons Science and Technology Committee resulted in provisions on legislation such as the Clean Neighbourhoods and Environmental Act 2005. If you want to check light pollution where you live, this map of the UK shows levels of radiance affecting the night sky.

Reducing light pollution in construction In building services, the importance of outdoor artificial lighting is essential. In community developments outdoor lighting enables sports to continue into the evening, in schools outdoor lighting is essential for recreation and of course for most buildings, outdoor lighting is key to security and keeping occupants safe. In fact the implication of light pollution in new developments can have an effect on assessments and planning permission – so if you are a developer or in the building services industry I recommend you check the following factors; light should not spill beyond the boundary of the area being lit and should not be near or above the horizontal (thus affecting the sky). If artificial lighting is determined in the planning stage and it is designed and installed well, on-going maintenance is also important to ensure effectiveness. Furthermore, measures such as automatic switch off at quiet times or when the building is closed should be considered. This is also ideal for legislations affecting domestic properties like Energy Performance Certification (EPC) which is required when a home is rented or sold.

Reducing light pollution at home If you aren’t involved in building services but you still want to make an impact in the amount of light pollution your home or business produces, here are some tips that I have discovered. For more information take a look at the British Astronomical Association’s Good Lighting Guide

Tips to reducing light pollution – Question the lighting you have in your garden as well as the positioning of it

– Use motion sensor outdoor lighting

– If you own a shop with a light up front, ensure it is off during daytime or when the shop is closed

– Use lighting with hoods on to direct the light downwards

– Avoid up-lighting which is popular outside restaurants and night clubs

– Opt for warm and low light temperatures

– Invest in lighting that can be dimmed