Posted by Ellery McNaughton @EJ_McNaughton
Like Santa, ALAN probably sees you when you are sleeping. ALAN will be trying to get in through your window tonight. Perhaps you haven’t noticed ALAN. But ALAN is always there. ALAN may be having serious impacts on your health. ALAN kills innocent birds and baby turtles for fun.

ALAN will be following you home tonight… and when you get there, ALAN will already be waiting for you
And yet, who doesn’t love ALAN? Who hasn’t invited ALAN into their homes and cities?
Artificial Light At Night (ALAN) is a global issue. If you live in an urban area you cannot escape it. Streets, buildings, sports fields, parks, monuments – all are lit up come night time, and it’s easy to see why. Light enables us to see better, feel safer and do more at night. Plus it looks pretty. Bonus!
Light pollution doesn’t get the same attention that water or air pollution does. Perhaps this is because it doesn’t add a physical pollutant to the environment. Perhaps it is because it is seen as transient – once the lights are switched off in the morning, problem solved. Or perhaps it is because we have forgotten what the night sky should look like, so we fail to realise just how polluted our skies are. Whatever the reason, traditionally light pollution has only been an issue of concern among astronomers.
Recently however, there is light on the horizon in addition to light in our skies. There has been a surge of research into the myriad effects of ALAN on the environment (e.g. this special issue in Proc. R. Soc. B). Citizen science is being used to better understand variations in the levels of light pollution. The United Nations proclaimed 2015 to be the International Year of Light and Light-based Technologies, while the Nobel Prize in Physics for 2014 was awarded to the inventors of the blue light-emitting diode. This recent focus on light, light technologies and ALAN in particular opens up opportunities for discussion and thought on these issues. And really, this needs to happen. Because ALAN is most definitely on the naughty list, and we need to talk about it.
Ellery McNaughton is a PhD student in the Centre of Biodiversity and Biosecurity, School of Biological Sciences, University of Auckland. Her project will investigate the effects of a city-wide changeover in streetlight technology on urban bird behaviour and ecosystem function. She is supervised by Margaret Stanley, Jacqueline Beggs, Kevin Gaston (University of Exeter, UK) and Daryl Jones (Griffith University, Australia).