The and brightness of light from towns and cities around the world is at a high level that it is reducing the of night. Once upon a time, when night-time fell, we were plunged into darkness. Things are different, and today. A study published in the journal Science Advances reports that artificial at night is increasing in most countries . Scientists say it grew by 2.2 per cent a year between 2012 and 2016. The of artificial light into our night-time is causing us problems. The International Dark-Sky Association says it, "is not only impairing our of the universe, it is adversely affecting our environment, our safety, our energy and our health".
Study co-author Franz Holker said light is a threat to our natural . He said: "Artificial light is an environmental that threatens nocturnal animals and affects plants and microorganisms." He added: "[It] has and evolutionary implications for many organisms from bacteria to , including us humans, and may reshape entire ecological systems." Many environmentalists thought the of LED lights would help the planet. However, are using more LED because they are cheaper, which is adding to the light pollution. Night-time light decreased in 16 countries, including war-torn such as Yemen and Syria.