Light pollution levels differ drastically across geographical areas. Even within the same region/jurisdiction where lighting standards and policies are homogenous, light pollution still varies drastically. In Europe, there is a 6,800-fold difference between the most and the least polluted region– 120-fold difference in FpC and 267-fold difference in FpD (*FpC: Light flux per capita; FpD: Light flux per GDP unit). You may be wondering, why so?
Differences in FpC
Differences in FpC is attributed to the geographical size and location of the country, where light pollution is observed to be worst in larger and more urbanised cities, as compared to areas in mountainous provinces. Cultural differences across countries also affect FpC. In Europe, light pollution is worst towards the Southern countries of Portugal, Spain, Italy and Greece, as well as the Northernmost provinces of Finland, Iceland, Norway and Sweden, where the Northern-Southern difference in FpC has been attributed to different lifestyle and cultural consumption habits.
Figure 1: FpC in Europe
Differences in FpD
Differences in FpD is attributed to the level of affluence and population density of a country, where a cost-benefit approach is taken to determine the FpD. For instance, an affluent country with a high population density would rank the best in terms of FpD (i.e Paris), as the cost of adopting efficient technologies is lower and the efficient lighting serves a wider population base.
Figure 2: FpD in Europe
Analysis of FpC and FpD helps in the identification of root causes of light population, guiding policy-making for light pollution. It also allows us to see the complex nature behind this very simple problem (that is, light) – where there are many attributing factors interconnected to this problem. Hence, light pollution policies should be specific and targeted, based on the specific contexts of each country.
References
Falchi, F., Furgoni, R., Gallaway, T.A., Rybnikova, N.A., Portnov, B.A., Baugh, K., Cinzano, P. and Elvidge, C.D. (2019). Light pollution in USA and Europe: The good, the bad and the ugly. Journal of Environmental Management, 248, p.109227.