The LED Paradox: How Light Pollution Challenges Experts to Reconsider Sustainable Lighting

Abstract

In the 21st century, the notion of “sustainable lighting” is closely associated with LED technology. In the past ten years, municipalities and private light users worldwide have installed light-emitting diodes in urban spaces and public streets to save energy. Yet an increasing body of interdisciplinary research suggests that supposedly sustainable LED installations are in fact unsustainable, because they increase light pollution. Paradoxically, blue-rich cool-white LED lighting, which is the most energy-efficient, also appears to be the most ecologically unfriendly. Biologists, physicians and ecologists warn that blue-rich LED light disturbs the circadian day-and-night rhythm of living organisms, including humans, with potential negative health effects on individual species and whole ecosystems. Can the paradox be solved? This paper explores this question based on our transdisciplinary research project Light Pollution—A Global Discussion. It reveals how light pollution experts and lighting professionals see the challenges and potential of LED lighting from their different viewpoints. This expert feedback shows that “sustainable LED lighting” goes far beyond energy efficiency as it raises complex design issues that imply stakeholder negotiation. It also suggests that the LED paradox may be solved in context, but hardly in principle.

Spectral optimization of beacon lights for the protection of night‐swarming mayflies

“…From the aspect of ecological impact, the similarity of HPS lamps and PCA LEDs has been reported by Schulte‐Römer et al . (2019), but the colour rendering of PCA LEDs is better (Aubé & Simoneau, 2018). Longcore et al .…”

“…According to our former observations (Száz et al ., 2015; Egri et al ., 2017a), swarming of E. virgo falls within this time window with a high degree of certainty, hence the operation of the beacons are restricted to the swarming hours and the incidental negative impact of the beacons on the environment is minimized. This is a very important issue, because effects of blue lighting at night are not only wildlife‐related (Longcore et al ., 2018; Schulte‐Römer et al ., 2019), but humans can also be affected (West et al ., 2011; Schulte‐Römer et al ., 2019). Nevertheless, in our case, urbanized areas are separated by a dense line of trees from the beacon‐lit section of the river.…”

City Light or Star Bright: A Review of Urban Light Pollution, Impacts, and Planning Implications

“…Finally, LED’s expansion has created a rebound effect that nullifies gains in overall energy consumption by the sector (Saunders and Tsao 2012). Thus, LP concerns have intensified with the growth of nighttime illumination thanks in large part to the increased adoption of LED, even though the technology can also help with LP mitigation (Schulte-Römer et al 2019). LP from all sources, not simply LEDs, is of concern in this article.…”

“…Thus, while LED’s exponential growth risks nullifying energy gains of the sector, whether the technology can also help realize its potential for eco-friendly lighting in practice is a question posed by some experts. Schulte-Römer et al (2019, 6160) are hardly sanguine. They write, “in theory, customizable, controllable and color-changeable LED technology can fulfil the criteria of eco-friendly lighting.…”

“…Artificial light has facilitated the widespread disconnection of lifestyles and work schedules to day–night cycles and related circadian rhythms, permitting or requiring activity, sleeping, and feeding at times that may be physiologically suboptimal (DOE 2017; Pottharst and Konecke 2013; Wyse et al 2011). Spectrum, light level measured at the eye, duration of exposure, timing of exposure relative to an individual’s circadian cycle, and flicker and other forms of light movement all are believed to contribute to light’s effects on health, sleep, mood, and vigor (Curcio et al 2016, and others cited in Schulte-Römer et al 2019).…”