Earth's night 'getting brighter' as light pollution increases

Harriet Pavey
The distinction between day and night is disappearing, scientists say: Pixabay

The Earth’s night is “getting brighter” as artificial light pollution grows and becomes more extensive year on year, new research has shown.

A study of pictures of Earth by night found that between 2012 and 2016, the planet’s artificially lit areas grew by more than two per cent each year.

Scientists described a widespread “loss of the night” with half of Europe and a quarter of North American “experiencing substantially modified light-dark cycles”.

This rapid increase in light pollution could have negative consequences for “flora, fauna and human well-being”, the authors of the study said.

Lead researcher Christopher Kyba of the German Research Centre for Geosciences said that the introduction of artificial light was "one of the most dramatic physical changes human beings have made to our environment".

He told BBC News the findings were not what he predicted: "I expected that in wealthy countries - like the US, UK, and Germany - we'd see overall decreases in light, especially in brightly lit areas.

"Instead we see countries like the US staying the same and the UK and Germany becoming increasingly bright."

Much of the increase in artificial light occurred in Asia, specifically West Asia, Africa and South America.

Only a few countries showed a decrease in brightness, such as Yemen and Syria – both of which are experiencing warfare.

Since the satellite sensor that produced the images cannot detect the bluer light humans can see, the increases in brightness are likely to be even greater than shown.