The distinction between day and night is fast disappearing in heavily populated regions, researchers said in a paper published on Wednesday in the journal Science Advances.

“The world has experienced widespread ‘loss of the night’, with half of Europe and a quarter of North America experiencing substantially modified light-dark cycles,” the authors of the study said.

This rapid increase in light pollution has far-reaching consequences for the health of people and the environment, they added.

Annual rate of change for both lit areas and the radiance of areas that have stable lighting.

Artificially lit areas increased by 2.2% annually between 2012 and 2016, Christopher Kyba of the German Research Centre for Geosciences said, noting that “earth’s night is getting brighter”.

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

These findings, however, may have understated the actual rise in lit areas, since the satellites that the researchers used are not sensitive to blue light wavelengths, which are emitted by LED lights, the Washington Post reported.

A study published in October found that artificial lighting near waterways draws insects towards the source of the light. This disrupts food chains and harms the local ecosystem. A study published in 2016 said there was a correlation between increased lighting in beaches and a decline in sea turtle populations.