Light pollution: Everything you need to know

Light pollution, caused by human development and poor fixture design, affects over 80% of the global population. It disrupts human circadian rhythms, increases risks of chronic diseases, and severely impacts wildlife migration, reproduction, and plant cycles. The document identifies four types of light pollution—skyglow, glare, light trespass, and clutter—and links the issue to energy waste, noting that at least 30% of outdoor lighting in the U.S. is wasted due to unshielded fixtures.

• Light pollution is categorized into four primary types: skyglow (urban artificial brightness), glare (discomforting bright light), light trespass (unintentional beaming into areas like bedrooms), and clutter (bunched light sources causing confusion).
• The prevalence of light pollution is widespread, with a 2016 Science Advances study indicating that more than 80% of the world's population lives under light-polluted skies, rising to over 99% for people in Europe and the United States.
• Artificial light at night disrupts human health by interfering with circadian rhythms and is linked to higher rates of diabetes, sleep disorders, obesity, depression, and certain cancers, specifically prostate and breast cancer.
• Light pollution negatively impacts various wildlife species: it disorients migratory birds leading to millions of deaths annually, disrupts sea turtle nesting and hatchling navigation, alters the activities of nocturnal bats, and causes a 'temporal mismatch' in plants by triggering premature budding and flowering.
• There is a direct link between light pollution and energy inefficiency; the International Dark-Sky Association estimates that at least 30% of all outdoor lighting in the U.S. is wasted because fixtures are unshielded.

APA

Morawski, B. R. (2023). Light pollution: Everything you need to know. World Economic Forum. https://www.weforum.org/stories/energy-transition/light-pollution-everything-you-need-to-know/

Chicago

Morawski, Bridget Reed. Light pollution: Everything you need to know. World Economic Forum, 2023. https://www.weforum.org/stories/energy-transition/light-pollution-everything-you-need-to-know/.

Wikipedia

{{cite report |last1=Morawski |first1=Bridget Reed |title=Light pollution: Everything you need to know |publisher=World Economic Forum |date=25 January 2023 |url=https://www.weforum.org/stories/energy-transition/light-pollution-everything-you-need-to-know/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{morawski2023light, author = {Morawski, Bridget Reed}, title = {{Light pollution: Everything you need to know}}, institution = {World Economic Forum}, year = {2023}, month = jan, url = {https://www.weforum.org/stories/energy-transition/light-pollution-everything-you-need-to-know/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }