Lights on & lights out by John Nelson

As a follow-up to last week’s visualization of Old Light and New Light, I wanted to make a single map, of the whole world, comparing NASA’s new 2016 Earth At Night image to the 2012 version. Using a simple pixel-difference math bot, this map isolates places where lights have come on (or increased) and where they have gone off (or decreased) in the past five or so years.

There are lots of interesting changes to the nighttime sky in these last recent years. Some optimistic and exciting, and others terribly sad.

In the map’s text I lay out some hunches for what might cause lights to come on in some places and some reasons I suspect for lights that have been extinguished.

Some reasons for new nighttime illumination are suburban growth rings around existing urban centers, the new electrification of rural areas, wellhead fires in areas of new petroleum extraction, or waters newly popular with fisheries.

Some reasons for dimmed or extinguished nighttime illumination are the preventative measures taken to reduce nighttime light pollution, the contraction of populations from economically struggling areas, the abandonment of petroleum fields or fisheries, or the collapse of population or infrastructure due to war or social upheaval.