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APPG for Dark Skies – Light Pollution

Light Pollution affects society and habitats in several ways; stargazing and astronomy are just the tip of the iceberg.  Animals affected by light pollution include migrating birds, butterflies and moths, wasps, diurnal insects, plankton, (fresh water and sea water), sea turtles, many nocturnal animals and insects.  In particular, insects whose visual range includes Ultraviolet and is highly sensitive to blue light, are more affected by light pollution, as are insects and animals who utilise polarised light, e.g. dragonflies and other water breeding/feeding insects mistake the polarized light reflecting off roads for light reflecting off water and will unsuccessfully attempt to breed or feed on roads.

Humans have long since been affected by light pollution, mainly due to disruption to normal sleep patterns or circadian rhythm.  In June 2019, the International Agency for Research on Cancer (IARC) Monographs Vol 124 Working Group classified night shift work as a probable carcinogen to humans (Group 2A).  Also, famously, astronauts have long suffered from insomnia and for many years this was attributed to the excitement and workload, or weightlessness and other environmental factors.  However in August 2016 colour changing LED lighting was installed on the ISS ( with the (successful) aim of improving the astronauts sleep patterns by mimicking natural light changes during the day and at sunrise and sunset.

There is an ever-increasing body of evidence which demonstrates that light pollution affects human health in many negative ways.  Light pollution from invasive streetlights, after-hours commercial lighting and phones and devices in our homes are keeping us awake long after we should have fallen asleep.  Headaches, stress, anxiety, diabetes, hypertension, (leading to heart disease, erectile dysfunction), an increase in adrenaline due to an incidental activation of the fight or flight response are just some of the results.

The UK has an exponentially growing Astro Tourism Industry. Kielder Observatory, Battlesteads Observatory, the Scottish Dark Sky Observatory in Galloway, and Jodrell Bank in the Midlands are the main centres where people flock from all over the Earth to experience dark unfettered views of the universe.  More recently many amateur astronomers have turned professional and are leading tours of the skies across Great Britain and Ireland.  This is having a knock-on effect in terms of uplifting other incomes in businesses such as accommodation and restaurants.  More importantly this is off season income for businesses that usually have their peaks during the summer months, (e.g. Battlesteads Observatory now have a consistent 80% occupancy levels, even during the winter.)  A recent study conducted for National Parks in the UK conservatively indicated that only a couple of years ago in its infancy, astrotourism was responsible for an additional £25,000,000 worth of tourist income.  This also has the effect of improving employment, directly within the astrotourism industry and in all the associated accommodation/restaurant businesses.

Light pollution is a risk factor for astrotourism, increasing incomes and employment, particularly in the “off season” (stargazing is best done in the dark skies of winter.)

Recommendations for Governments

Government outlines laws to mandate for the following:

All future outdoor “white lights” whether commercial or street, to be low colour temperature LED lighting (LESS than 3,000 Kelvin).

All future lights to be “downlight” and fully shielded only.

Street lights to automatically dim at 10PM, and then again at 11:30 and then turn off at midnight (local variations allowed due to late night businesses need.) Lights to come back on (dimmed) at 5am, then full until sunrise. (These times notwithstanding things like sunset times between summer and winter, and the differences in darkness levels from geographical south/north of the UK – I would be happy to consult on this.)

Commercial, manufacturing, office lights to be switched off out of business hours.

New builds, (of anything whether commercial, council or residential) to have low temperature lights, down lit (no lights shining up into the sky!)

A tax or fines for light polluting businesses which is directly funneled to local educational and conservation projects.


Further worth nothing: often that light pollution doesn’t come from local sources, but from distant cities. LP doesn’t respect jurisdictional boundaries – “photons without borders” (q.v. Landscape-scale protection of dark night skies needs public policy support well beyond the local level.