We often don’t think of how we light our cities, but lighting in urban environments is an important piece of city design and residential safety.  Our relationship with space and each other is largely influenced by light. It provides safety; it is a source of visual interest; it displays ads, art and information; and it directs movement and access to certain spaces.

But outdoor light is also a huge user of energy.  Light pollution is increasing by 10 percent a year. The way cities design public lighting has implications for energy use, public health, how public space and streetscapes are used, as well as the overall character of an urban environment. Local Governments for Sustainability (ICLEI), an association of local government groups, said that good public lighting increases the number of people who tend to use an area and makes people feel safer, but it’s important to make sure lighting is not excessive.

Enlight is a European project supported by the European Commission designed to promote energy efficiency in the lighting of outdoor areas. Case studies highlight practices that include converting mercury lighting to more efficient measures, installing computerized and motion-detected lighting systems, and expanding the use of solar cell lightning.  For transportation and streets, specifically, illuminated crosswalks and halogen headlamps on cars improve drivers’ visibility of pedestrians on the road.

Another advocacy organization called the International Dark-Sky Association “preserves starry spaces for future generations” by focusing on light pollution from urbanization. In the public realm, the advocates hope to keep the sky clear of excessive light by focusing on motion-sensored light and lighting that projects downwards rather than upwards. The mission of the US-based organization, Dark Sky Society, is to “preserve and protect the nighttime environment and our heritage of the dark skies through quality outdoor lighting.”

In 2000, the United Nations Development Programme financed a sustainable lighting project in Vietnam that included the lighting of streetscapes, hospitals and schools.  According to the Clinton Climate Initiative, 85 percent of street lighting in Vietnam is made of mercury or incandescent lamps that are wasteful and costly to maintain. Vietnam Energy Efficient Public Lighting Project (VEEPL) – with a UNDP loan – established standards for energy efficient public lighting and developed “improved testing capabilities of local lighting laboratories.”

The American Medical Association also says wasteful and unnecessary light poses health problems: “the increasing amount of light in the world, including streetlight glare and intrusive light…is linked to higher rates of cancer and other human health problems. It reduces the production of melatonin, a hormone that helps regulate sleep cycles, and hampers the immune system…”

Given the health and environmental implications of excessive lighting in cities, it seems we might be more citizen involvement and awareness might bring the issue to better light. For example, residents could track their concerns on the participatory website, SeeClickFix, that documents issues with public safety, repair and citizen concerns.