The Biophilic Cities Project had the honor of hosting author of The End of Night: Searching for Natural Darkness in an Age of Artificial Light (Little, Brown and Company) and professor, Paul Bogard, this past month. As a creative non-fiction writer, Bogard has a special way of sharing the research and telling the narrative of our innate connection with the night sky and the loss of visibility of the night sky due to light pollution.

Artificial, unshielded light prevents us from connecting with the night sky, wastes valuable resources, and negatively affects wildlife. There are four main forms of light pollution including, glare, sky glow, light trespass, and clutter. Bogard is deeply passionate about this topic as he discusses the problems with light pollution, common misconceptions, and potential remedies.
Bogard begins one of his lectures by explaining, “Artificial light at night is a good thing. Light can help us be safer and more secure. Unshielded lighting that shines in all directions is light pollution. Light is good, but rather than using it wastefully, we want to use it thoughtfully and responsibly.”
The End of Night was inspired his own experience growing up in Minnesota with a captivating night sky. In the book he explains through stories, the negative effects of light pollution, misconceptions about the amount of light that we need, and what cities can do to help protect the health of humans and wildlife.

The Problem of Light Pollution

Light is something that we expect to see at night. An abundance of light floods our shopping centers, highways, and neighborhoods, but is that light being used effectively? Bogard demonstrates how light is often not directed where is most beneficial, but often beams in the wrong direction or in all directions. This has negative impacts on wildlife, including birds and sea turtles, and human health. Bogard shares that “Sixty percent of invertebrates depend on darkness.” There are other environmental impacts to consider when 30% of light that is produced is wasted. This inefficient use of light is an extremely inefficient use of natural resources.
As I mentioned above, there are four types of light pollution and Paul discusses the issues with each.


Glare is the type of light pollution where rather than the light going in the specific direction where it is needed, it radiates out. This is very challenging for our eyes, especially as we age.

Sky Glow

Sky Glow is when the light pollution is so bright and uncontrolled that it illuminates the sky creating a glow effect.

Light Trespass

Light Trespass is when light is that intended for one purpose, such as providing light for those who in live in this neighborhood, but it encroaches on others that the light was not intended to brighten.


Clutter is when there are so many lighting fixtures that there is overlap in coverage of lighting.

All of these forms of light pollution have contributed to a night sky that is clouded with light to the point where stars cannot be seen. The Bortle Scale helps us assess the level of darkness with a scale of 1-9. A score of 1 would indicate an excellent, naturally dark sky. Bogard shares that level 1 dark skies are such a rare siting that one evaluator has only given this score to three locations in the United States. Most Americans have never experienced a dark sky below a level 5.

Light Misconceptions

Bogard emphasizes that this is not just a problem for astronomers. The main reason cited for the abundant use of light at night is safety, but more light does not necessarily equate to safer environments. The overabundance of light can make it more difficult for our eyes to see a potential threat that may be only a few feet away from us. It also negatively affects other aspects of our well-being. Artificial light at night has been associated with increased cancer rates, low melatonin production, and depression.


We need darkness for so many reasons. Because of its significance, the National Park Service now considers darkness a natural resource. Lighting strategies in cities across the world need be amended to be thoughtful and responsible. Local ordinances can help enforce the appropriate types of fixtures that shield light from polluting our environment. Communities can also go through the process of becoming a Dark Sky Community, sponsored by the International Dark Sky Association. Lastly, educational events, such as stargazing, can help citizens become aware of the issues with too much artificial light in our cities and neighborhoods.

To learn more about Paul Bogard’s book, please visit

To view the public lecture Paul Bogard gave at the University of Virginia, please visit