The lighter side: A changing Earth at night

NASA’s recent release of a new Earth at night composite image is the first release of a new global map of night light distribution since 2012. Since their previous release, NASA has worked on an improvement of the underlying algorithms that provide clearer and more accurate imagery from the raw satellite data.
The latest version (shown as a small inset map in this cartogram feature) is not only the most accurate picture of light intensity around the globe, but the underlying data also allows a direct comparison of the changes that occurred between 2012 and 2016. For achieving this, the datasets of the two years were corrected for the changing light effects caused by the moon as well as “seasonal vegetation, clouds, aerosols, snow and ice cover, and even faint atmospheric emissions (such as airglow and auroras)” which “change the way light is observed in different parts of the world”. Both datasets also cover the period of a full year to take seasonal changes into account.

Cartogram of Changes in the Earth at Night imagery
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Europe at Night

Earth HourNASA’s night lights imagery published in the Earth Observatory provides a stunning view of our impact on the planet. The following map of Europe at night is an extract of my gridded population projection of the the Earth at night showing more detail of where the distribution of night lights is on the European continent in relation to its population distribution (the surrounding areas such as the northern tip of Africa remain unchanged, hence shows a ‘normal’ land area perspective). Europe is one of the few regions globally (alongside North America) where light pollution at night is very much a phenomenon that is ‘normal’ for the vast majority of people who see very little of the night skies (hence the dominantly bright areas in this image – dark spots are those areas where people live with very little light pollutin). Northumberland Dark Sky Park (which gained Dark Sky Status by the International Dark-Sky Association in December 2013) is now to be known as Europe’s biggest Dark Sky Park and the largest unspoilt area in this regard, squeezed in the sparsely populated bright spaces between Northern England and Southern Scotland in this cartogram:

Equal population projection map of Europe at Night
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Earth at Night

Earth HourIn 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:

Equal population projection map of the Earth at Night
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Views of the World at Night

The Sendai earthquake in Japan sparked a debate about sustainable energy supplies of industrialised countries – with a controversial discussion about the safety and sustainability of nuclear power. The book ‘Sustainable Energy – without the hot air‘ by David MacKay is an outstanding read in this regard, outlining the all key issues that matter for our future energy need (the digital version is free, although I recommend the paperback which can even be read without wasting any electricity).
Switching the lights off was not a matter of choice for many people in the North of Japan after the devastations of the earthquake also affected the energy supplies (not only because of the Fukushima accident, but also because of a widely destroyed basic infrastructure). Another image featured in the NASA Earth Observatory takes a closer look at the electricity losses that occurred after the Earthquake by creating a composite image of two images of lights observed in 2010 and after the earthquake at March, 12 this year. As a highly industrialised country, the illuminated areas in Japan usually show the places where people live (see worldmap below), while dark areas are the unpopulated regions, hence the reprojection on a gridded population cartogram results in a dominantly bright image. Using NASAs display of the electricity losses therefore gives a good representation of the number of people affected by the power losses (and largely also the Tsunami and Earthquake itself) in the Northeast: The redrawn version of the image shows these as the red areas, while the brighter yellow areas in the South and West show the regions that has a similar illumination compared to the previous image. This is how ‘Japan at Night’ looked after the 2011 Earthquake:
Japan at Night after the 2011 Earthquake displayed on an Equal Population Cartogram Continue reading