  Light pollution is a worldwide problem that has a range of adverse effects on
human health and natural ecosystems. Using data from the New World Atlas of
Artificial Night Sky Brightness, VIIRS-recorded radiance and Gross Domestic
Product (GDP) data, we compared light pollution levels, and the light flux to
the population size and GDP at the State and County levels in the USA and at
Regional (NUTS2) and Province (NUTS3) levels in Europe. We found 6800-fold
differences between the most and least polluted regions in Europe, 120-fold
differences in their light flux per capita, and 267-fold differences in flux
per GDP unit. Yet, we found even greater differences between US counties:
200,000-fold differences in sky pollution, 16,000-fold differences in light
flux per capita, and 40,000-fold differences in light flux per GDP unit. These
findings may inform policy-makers, helping to reduce energy waste and adverse
environmental, cultural and health consequences associated with light
pollution.

Physics and Society;Instrumentation and Methods for Astrophysics