A new map shows the extent of global light pollution

Scientists monitor pollution levels in the air as well as in the seas, lakes, and rivers. Now there is a simple tool to see another kind of pollution: artificial light pollution.

The light map above, taken from a live video streamed on the website Radiance Light Trends last week, shows which places on Earth are dark at night and which are still lit by artificial light.

According to physicist Christopher Kyba of the German Research Center for Geosciences in Potsdam, who coordinated the work on the map, thanks to this map we can see the level of light pollution on Earth, which is clearly observed by satellite on clear nights.

Artificial light interferes with the normal functioning of plants and animals that live in a world without light from buildings, streets and other artificial sources. In addition, light pollution is linked to human health problems, including sleep disorders and obesity.

Artificial light also poses a problem for astronomers, as they need a very dark night sky to make accurate observations.

The Radiance Light Trends website is part of the EU-funded GEOEssential project. Users can zoom in on the map to see how light pollution has affected specific areas over recent decades.

Kyba hopes the tool will be useful to both scientists and anyone interested in light pollution. The map combines data from satellites that were used for primary work between 1992 and 2013 but have since been retired. The Suomi National Arctic Observation Collaborative satellite, operated jointly by NASA and the National Oceanic and Atmospheric Administration, provided the data from 2012 to the present. The map is automatically updated as new images are sent back from the satellites.

Mr. Kyba and his colleagues are studying how artificial light and nighttime illumination of cities are changing, and he plans to create similar maps to track changes in sea ice, air temperature, and leaf-out, contributing to creating new tools for other fields of research.