Irish Examiner View: We must save our starry, starry nights

New research warns that the night sky is brightening by 9.6% on average globally each year, much worse than previously thought

Kerry International Dark-Sky Reserve, Derrynane, Co Kerry. Picture: Valerie O'Sullivan Wild Atlantic Way

Here in Ireland, we are lucky to be able to experience the night sky in all its profound glory without the intrusion of polluting manmade light. It is one of the ways we can share experience with our ancestors down the millennia.

The island of Ireland is home to three of the darkest skies in Europe with the Kerry International Dark Sky Reserve and the Mayo Dark Sky Park joined by Davagh Forest Park in the North in enjoying a “Gold Tier” rating from the International Dark Sky Association. 

In addition, there are dozens of other locations where a patient and reflective visitor can enjoy a humbling and replenishing night-time vista.

Wilderness Ireland tells us that on a clear night you can see over 4,000 twinkling stars, planets such as Venus or Jupiter and even meteor showers with the unaided eye. Such viewpoints are up to 40 times darker without the intrusion of city lights.

But we must not take this celestial joy for granted, as scientists warn that by the time a child born today reaches adulthood, they will see fewer than half the stars visible to them today. 

The German Research Centre for Geosciences warns that the night sky is brightening by 9.6% on average globally each year, much worse than previously thought. The Royal Astronomical Society warns that the fainter constellations — such as Cancer — and the Orion nebula and Andromeda galaxy may fade away completely.

New research involving more than 51,000 citizen scientists worldwide drew data from 19,262 locations before concluding that the rate of change was faster than previous estimates. In Europe it was slightly below average at 6.5%, while in North America it stood at 10.4%. Accepting that there is a problem is one thing. Responding to it is another. 

Researchers, who published their work in the journal Science, recommended that shutting off advertising signs at night and avoiding the proliferation of “cold white lighting” could be a major benefit.

Treating light intrusion as we would other forms of pollution would also be significant. In this energy-strapped century, that seems like a win-win.