The problem of light pollution in cities is becoming increasingly serious, which is mainly due to the following reasons:

The excessive development of urban lighting systems:

With the process of urbanization, urban road lighting, night lighting and other bright projects continue to increase, making the city become extremely bright at night. This excessive lighting not only wastes a lot of energy, but also leads to the generation of light pollution.

Research by Christoph Kiba of the German Center for Geosciences shows that light pollution is causing the night sky to brighten at a rate of about 10% per year. This figure directly reflects the seriousness of urban light pollution.

Unreasonable lighting design:

Some cities have unreasonable lighting designs, such as the use of excessive lighting fixtures, or improper installation positions and angles of lamps, resulting in direct light exposure to people’s eyes or sensitive areas, causing glare and light pollution.

Decorative materials such as glass curtain walls and glazed brick walls of some buildings will reflect light, increasing the degree of light pollution. According to the measurement, the light reflection coefficient of the white whitewashed surface is 69% ~ 80%, and the reflection coefficient of the mirror glass is 82% ~ 90%, which is much more than the range of the human body can withstand.

Lack of effective light pollution control and management measures:

At present, there is no specific legislation for light pollution in China, and complaints involving light pollution are supervised by multiple departments, leading to difficulties in light pollution control.

At the same time, due to the lack of effective light pollution control and management measures, some enterprises and individuals in order to pursue visual effects and economic interests, excessive use of lighting equipment, aggravate the degree of light pollution.

Public awareness of light pollution is low:

Compared with environmental problems such as water pollution and air pollution, the public’s understanding and attention to light pollution is not enough. Many people do not realize the impact of light pollution on the environment and health, and lack the awareness to prevent and control light pollution.

To sum up, the causes of serious urban light pollution mainly include the excessive development of urban lighting systems, unreasonable lighting design, the lack of effective light pollution control and management measures, and the lack of public understanding of light pollution. In order to reduce the impact of light pollution, it is necessary for the government, enterprises and the public to work together to strengthen the publicity and education of light pollution, formulate effective light pollution control and management measures, and promote sustainable urban development.