In 2007 nature conservation organisation WWF initiated a campaign “encouraging households and businesses to turn off their non-essential lights for one hour to raise awareness about the need to take action on climate change” (Wikipedia). The campaign is called Earth Hour and always takes place at the end of March – this year on Saturday, the 23rd.
The Earth Hour campaign has motto of “uniting the world to protect the planet”, although certainly not everyone will join in switching off their lights at 8.30 pm to unite each time zone with a dark night sky (and there is criticism of campaigns like this). But the wealthier parts of the world will be the main focus, as large parts of the poor world live in relative darkness at night anyway. NASA’s composite satellite image of the world at night (as featured on this website before) that gives us an indication of where light pollution affects most of the night skies has just received an update recently. Earth at Night 2012 was published by the NASA Earth Observatory last December, promising nothing less that “It’s the end of the night as you know it; you’ll see fine.” The resolution and level of detail revealed in the data is stunning, so that I reworked my version of the Earth at Night in an equal population projection using a gridded cartogram transformation. The new gridded population cartogram of the Earth at Night gives an equally stunning insight into how human activity relates to the distribution of light at night, showing the already highlighted inequalities that became apparent in the old version of the map in even greater detail where large parts of the populations in Africa and also in some parts of Asia live in the shadows of the wasteful brightness of the wealthy world. The Earth at Night as seen by humanity – an image of an unequal world:

(click for larger version)

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