Lights On & Lights Out

The comparative illumination of the night sky between 2012 and 2016. Areas of new nighttime light are shown in blue areas of extinguished nighttime light are shown in magenta.

Light on (blue)
Some reason for new nighttime illumination is suburban growth rings around existing urban centers, newly built transportation lines, the electrification of rural areas, or wellhead fires at new petroleum extraction sites.

Light out (magenta)
Some reasons for extinguished nighttime illumination are the collapse of population or infrastructure due to war or social upheaval, the contraction of populations from economically struggling areas, or preventative measures taken to reduce nighttime light pollution.

Lights On & Lights Out

Source: John Nelson (
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Ecoclimax is defined by Odum (1969) as the culmination state after a succession in a stabilized ecosystem in which maximum biomass (or high information content) and symbiotic function among organisms is kept per unit of available energy flow.