Increasingly intense Christmas lighting has been linked to higher light pollution, a pressing issue in many cities as it disrupts nocturnal wildlife, complicates stargazing, and interferes with the sleep patterns of people. In extreme cases like Vigo, the impact could be echoed in other parts of Spain, potentially causing lasting damage to ecosystems and public health. Scientific findings suggest that such bright displays can influence disease risk by altering circadian rhythms. Consequently, the Ministry of Ecological Transition and conservation groups have urged a gentler approach to holiday illumination.
Organizations such as SEO/BirdLife and Ecologistas en Acción have urged municipalities away from what some call a festive “lights race,” arguing that the surge in energy use harms biodiversity and urban ecosystems.
Moreover, the expansion of public space lighting and the accompanying light pollution is well documented, particularly affecting insects and certain bird groups. Insects are rapidly declining worldwide, a trend that can cascade through food webs and disrupt numerous species in urban areas, including Vigo and Cantabria.
Examples of light installations in botanical settings and public parks include notable sites like the Palmetum in Tenerife, the Torre Girona gardens in Barcelona, and the Enrique Tierno Galván park in Madrid, as well as tree-lined streets and avenues adorned with lights. These displays contribute to the usual rise in illumination during the holidays and reflect a lack of sensitivity toward the needs of wild species living in cities.
Most animals are nocturnal
In this context, Alicia Pelegrina, environmental sciences researcher at the University of Granada, notes that roughly 30 percent of vertebrates and 60 percent of invertebrates are nocturnal. Noise and light pollution disrupt sleep, hormonal cycles, and avian navigation, undermining a species’ daily rhythm.
Plant life is not immune either. Artificial lighting alters food webs, flowering times, and plant growth, affecting ecosystem dynamics across urban landscapes.
“30 percent of vertebrates and 60 percent of invertebrates are nocturnal.”
Ecologists in Action criticize leaders in sectors such as automotive and fossil fuels, accusing large multinational corporations of promoting greenwashing campaigns amid the climate emergency.
Vigo’s extreme case
SEO/BirdLife has highlighted the promotion of an unsustainable city lighting model and cites Vigo as an example. The decoration of a total of 2,308 trees this year may provide winter roosts for sparrows, wagtails, and other birds, with limited nearby resting options currently available nearby.
Environmental advocates warn about the effects of artificially altering light levels on rest, communication, reproduction, behavior, predation, and competition across species, underscoring direct impacts on ecosystem functioning. Humans are not exempt from these challenges either, as disruptions to biological clocks can affect sleep, eating patterns, digestion, hormone balance, and even body temperature regulation.
Minister calls for containment of lighting
The Minister for Ecological Transition and Demographic Challenges emphasized the need to curb excessive lighting spending while recognizing the desire to celebrate. The message was clear: coordination with local authorities is essential to balance festivity with restraint. In discussions about Vigo and other cities, where millions of LED lights are deployed, the goal is to improve efficiency while reining in decorative use of light.
It was pointed out that energy efficiency has improved, but a careful assessment of where and how lighting is used remains crucial. The debate about decorative lighting in historic buildings continues, with an emphasis on public understanding. Beyond extraordinary circumstances that require decree-based decisions, households and cities should adopt resource-conscious practices and consider flexible approaches to ornamental lighting when appropriate.
The conversation around lighting remains ongoing, with a focus on sustainable choices and responsible use of public resources that respect both festive spirit and ecological health.