Light pollution in USA and Europe: The good, the bad and the ugly

TL;DR

This study compares light pollution levels across regions in the USA and Europe, revealing vast disparities that can guide policies to mitigate environmental and health impacts of artificial lighting.

Contribution

It provides a comprehensive comparative analysis of light pollution disparities in the USA and Europe using multiple data sources, highlighting the scale of regional differences.

Findings

Europe shows up to 6800-fold differences in pollution levels.

US counties exhibit up to 200,000-fold differences in sky pollution.

Significant disparities in light flux per capita and GDP across regions.

Abstract

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.