In my final article for this season I would like to focus on something that perhaps we all take for granted…
Our Dark Sky
It is very easy to forget that we and wild species have evolved to operate in both daylight and night time. Artificial light removes a natural part of a time that wildlife uses to rest, migrate, hunt, hide and function during the day time. As humans we can close the curtains and turn off the lights inside our homes at will. Wildlife does not have such control and becomes vulnerable, having learnt to live and rely on the cover of darkness. Keeping our skies dark protects those natural ecosystems. Here in Embsay many people are lucky enough to gaze into a dark night sky. It is a gift, part of the character of where we live and something we must protect and value. Of course, light is necessary but stray light, overly intense, or misdirected, is not. It also impacts on our well-being, balance of sleep and wakening time. The increase of light at night decreases our melatonin production which results in sleep deprivation. The type of light has an impact too. High intensity light, which can be energy- efficient, emits more UV light that we can’t see but some wildlife can. Our LED street lights are pointed downward but are extremely intense and focused. These lights are rich on the blue wavelength which is now known to damage your retina. Finally, it uses energy which as we know is costly and in many cases is derived from using fossil fuels.
The night sky is a way in which we can connect with the wider universe and understand our place so to lose it is to lose something bigger than us.
So please think before you install an outside light. Is the light shining upward and just lighting the sky? Can it be shielded in some way? Does it need to be on? Can it come on just when something moves or just when you need it to? Keep your curtains closed and keep your light inside.
The Bortle Scale
This is a scale that measures the night sky’s brightness. 9 represents inner-city skies through to 1 being excellent. I believe that Embsay is currently Bortle 4/5 and currently lies in the suburban/rural category.
A rough test you can do during the summer months is to try to spot the Milky Way. Iif you can see it across the sky but it looks washed out and invisible at the horizon then we have a Bortle 5 or lighter sky. The more lights we point upward the closer to the left on the diagram we move. The more houses that are built (and associated lighting) the greater the erosion of our night sky. It is with some irony that the Yorkshire Dales National Park Dark Sky Reserve was granted in 2020 and a few years later is considering building housing developments in our village that will inevitably reduce our ability to have a dark sky.
The impact on our dark skies can be seen dramatically at www.lightpollutionmap.info .If you click on the link and search for Embsay then zoom in you will see how it has changed over recent years by adjusting the’ VIIRS’ in the overlay menu top right.
Clear Skies
Milan Davidovic
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