Why the nights are getting brighter – but not in a good way

Spread of light pollution is bad for the environment, animal life and humans, five-year study concludes

The world's nights are getting alarmingly brighter - bad news for all sorts of creatures, humans included - as light pollution encroaches on darkness almost everywhere.

Satellite observations made by researchers during five consecutive Octobers show Earth's artificially lit outdoor area grew by 2% a year from 2012 to 2016. So did nighttime brightness.