Monday, May 16, 2016

Night lights and prosperity don't always go hand in hand

North Korea is famously dark compared to South Korea and China at night, and images like the one below are often used to demonstrate the consequences of its "unenlightened" policies.

Photo ISS043-E-247811 from the International Space Station ISS.
See more like this at Cities at Night.

I certainly wouldn't want to live in North Korea, but is it an absolute truth that bright lights indicate prosperity, and lack of bright lights poverty and backwardness? The border between Germany, Belgium, and The Netherlands would suggest otherwise:

The border of The Netherlands, Belgium, and Germany at night.
Image from an International Astronomical Union press release.

The area of Germany shown in the photo is part of the Ruhrgebiet, home to 8.5 million people and one of the most industrialized areas in Europe. Nevertheless, the comparison of Germany to Belgium and The Netherlands is nearly as visually striking as that between North and South Korea. This is at least partly due to German lighting policy: Germany rarely lights its Autobahns (highways), and cities and towns are conservatively lit, often intentionally not following the European (DIN) norms for street lighting.

Last year we published a paper that examined the differences in lighting between cities and towns in the USA and Germany. American towns of 10,000 emit on average three times more light per capita than German towns, and cities of 100,000 emit more than five times more light per capita.

Total light emission from cities in Germany and the USA compared to community population.
Figure 5 from "High-Resolution Imagery of Earth at Night: New Sources, Opportunities and Challenges".

Germany uses far less light than its neighbors and the USA. Despite this, it is a prosperous country that is highly visited by tourists. It has low crime rates (the burglary rate is only 1/3 of that in the brightly lit Netherlands and just over half that of Belgium) and low rates of death due to traffic (about 1/3 less per 1 billion vehicle kilometers than USA or Belgium).

So if bright lights aren't needed to attract tourists, reduce crime, or make driving safer, then why do so many cities have such bright lights? Now that's a $100 billion question.

Note: Thanks to Alejandro Sanchez de Miguel for sharing the two ISS images with me.

Update: If you liked this post and want to learn more, check out this blog's "view from your app" photo series, that often highlights how good lighting is about more than how bright lights are. Some other blog highlights are about what a single floodlight can do to a natural area, the promise and peril of LED lighting, and citizens push back on LED lighting.


  1. Hi!
    I would like to ask for permission to translate your blog post and use photos night photos from ISS on Croatian web page, which deals with problems of light pollution.
    If I get permission to translate post, please specify how should I provide credit for you and source of photos.

    Thank you very much,

    1. Dear Vedran,

      You have my permission to translate the blog post. For credit, please say that I wrote the English version, and provide a link to this page. Just use the same captions as I used for the photos.

      Thank you for sharing!