What is Light Pollution
"Artificial light at night has revolutionized the way we live and work outdoors, but it has come at a price. When used indiscriminately, outdoor lighting can disrupt wildlife, impact human health, waste money and energy, contribute to climate change, and block our view of the universe" The Darksky Chicago Chapter.
So, what is light pollution? Light pollution is the increase of light levels due to human-made light. Increased light pollution has caused many to ask, is this a problem, and how do we solve it? The rate at which light pollution increases is growing at an alarming rate, as more lights are being added, and preexisting light features are being upgraded to have more powerful bulbs. We need a proper balance of using light responsibly and safely.
Source: Dark Sky International
As Chicago has Transitioned to LED street lights, citizens and scientists alike have noticed the differences and the adverse outcomes. The Increased lumens and temperature of these bulbs may directly impact safety, tree health, bird migration, and even your health.
To learn more, please view our guide below, which includes some direct impacts and potential solutions.
Why is This a Problem
Light pollution can cause disruption; please read the following information to understand better how it may be affecting our neighborhood.
Tree Health:
Many may be familiar with how light pollution can affect animals, but did you know it can also affect plants? Trees are just some plants that can be affected by light shining on them every hour of every day. Trees use light for energy, but they also use it as a signal. This signal helps them regulate their growth and seasonal changes. A study conducted in Poland found that artificial light at night caused trees to develop their buds faster. Leaf development was also affected as that process was accelerated by 20 days due to the level of light pollution. They also concluded that exposing trees to light can affect their nutrient content.
This was a similar finding to a study conducted in China. This study found that light caused trees to grow differently. They found that the increased light exposure caused tree leaves to grow "tougher." When leaves grow tougher, they uproot the entire ecosystem. If leaves are tougher, they could become more challenging for insects to consume, endangering their population's survival. If insect populations decrease, birds that rely on this food source will also struggle to thrive, which may endanger the urban food chain.
Trees are central to insects' and birds' lives, but they also play a large role in human lives in an urban environment. They provide a necessary urban canopy to protect us by mitigating heat and cleaning our air. Protecting them by lowering the light levels is just one way to ensure the pillars of our ecosystem can thrive in our neighborhood and city.
Insects and Birds:
We previously mentioned how light pollution indirectly affects insects and birds; however, it also directly threatens their survival.
Insect populations have steeply declined; many have searched for the key causes. One research group of multiple researchers, in a journal article published in Elsevier, cited artificial light as one of the main reasons insect populations struggle, especially vulnerable species. They concluded that light pollution directly interferes with multiple insect species' development, movement, foraging, and reproductive success. They cite other disturbances as part of the decline but firmly believe that reducing light pollution would relieve some artificial pressures insect populations face.
Birds also experience similar disturbances from light pollution. One of the most significant effects of light pollution is its direct impact on birds' migration patterns. According to the US Fish and Wildlife Service, large urban centers that produce large amounts of artificial light "can cause confusion, disorientation, and exhaustion—directly impacting their ability to migrate." By disrupting migration patterns, light pollution directly impacts birds' ability to survive. Furthermore, the artificial light created by buildings can increase the rate at which bird-building collisions occur, posing an even more significant threat.
Birds and Insects are just two examples of how light pollution can affect urban wildlife. The problem of light pollution needs to be addressed to ensure the safety of migration and the protection of insect populations.
Human Health:
According to NASA, increased artificial light exposure has a direct impact on the circadian rhythm to which we have adapted for survival. With increased light at night, our biological clock fails to do its job. This can have long-lasting effects; according to Dr. Gian Xiao from UTHealth Houston School of Public Health, it "leads to a lot of health consequences down the road, like cognitive decline, heart disease, and cancer." They cited that it has to do with how light inhibits the production of melatonin, an essential hormone regulating our sleep cycle.
Further studies conducted by Harvard Medical School found that blue light at night is more potent at suppressing the secretion of melatonin, suppressing it twice as long as other forms of light. The LED bulbs that the City of Chicago has replaced emit this blue light. Normal light is already proven to affect human health, but adding LED bulbs to our neighborhood poses an even more severe threat.
Ways to Fight Light Pollution
Light pollution is a unique problem with simple solutions. According to the Earth Law Center, the first step is to make light more "efficient and beneficial. " While safety is still a priority in our city, we must ask ourselves: Is all the lighting necessary? Is the brightness of the lights too much? One group, the International Union for Conservation of Nature, answers these questions in its report The World at Night: Preserving Natural Darkness for Heritage Conservation and Night Sky Appreciation. Some of the guidelines that the IUCN included on how to light outdoor areas can be found below:
Necessity and Timing:
When planning outdoor lighting, the first question should be whether it is necessary or just for aesthetic purposes. Light is a powerful tool, but overused unnecessary light can lead to light pollution. The timing of this light is also important. Using automatic timers and motion detectors can help regulate the time the lights stay on, cutting back not only on light pollution but also on electricity costs.
Color and Brightness:
In addition to considering the necessity of lighting, one must consider its color and brightness. As discussed before, these aspects can affect humans, animals, and plants differently. The color temperature should be regulated to no higher than 2700k. This threshold is used by many as it is less disruptive but also provides sufficient and safe lighting for an area. As the image provided shows, the lights on the left side of the street are closer to this 2700k color temperature. Brightness should be regulated based on the situation, as most are different.
Proper Shielding and Angling:
Proper lighting is lighting with a purpose. With this concept in mind, proper lighting angling must be established. The appropriate angle should project the light on the desired area, but no more. Please refer to the figure below from the IUCN, which demonstrates the proper lighting angles of flood lights.
Source: IUCN
These are just some changes that can be made to preexisting light fixtures to alleviate some of the light pollution that affects our city. These strategies, as well as further legislation, are needed to see real change.
Current Legislation
Cook County:
The Cook County Lighting Ordinance (Ordinance 12-O-12):
Enacted by Cook County in February of 2012, this ordinance was very early for its time. Its purpose is to achieve effective and efficient lighting while protecting the natural environment, ensuring visual access to starry night skies, and preserving the safety and security of Cook County residents. This ordinance applies to all new and replaced lighting fixtures under the Jurisdiction of Cook County Departments. While this ordinance itself does not lay out specific plans for future implementation, it sets the precedent that the Cook County governing body will implement policies and procedures to ensure this ordinance and its goals are fulfilled.
Illinois Legislation:
The Outdoor Lighting Control Act (Bill SB3501):
This new act, which Governor Pritzker approved in August, is the first of its kind for the Illinois State Government. It establishes that any structure or land operated, funded, leased, supported, or owned by the State must follow lighting control requirements. This act is very similar to the ones seen put forth by other states and helps establish the precedent of light pollution control on the state level.
Other State Legislation:
Many State and Local governments have taken on the challenge of fighting light pollution. Over 20 states have introduced and adopted bills that begin to address the problem. State governments have used tactics such as requiring outdoor light fixtures to be shielded, preventing additional outdoor lighting installments, and requiring low-wattage bulbs. Check out some of the legislation below passed by other States to better understand how Illinois and Chicago can develop proper regulations that effectively tackle the challenge.
New York: Legislation prohibiting the use of state funds to install permanent outdoor lighting fixtures unless they meet requirements.
Texas: Legislation prohibiting the use of state funds to install or replace outdoor fixtures unless they emit only as much as necessary, maximize energy conservation, and minimize light pollution.
Maine: Directive that state planning office review commercial lighting standards for preserving dark skies.
Many states are paving the way to help secure the future of our dark skies. The laws, standards, and directives created by these states can help Illinois make decisions regarding our goals to mitigate light pollution.
Concluding Thoughts:
Light Pollution is a serious problem, one that we all have a stake in. Caused by increased brightness and color and improper usage, light pollution can affect our ecosystem; that being said, we all have a part to play. The time to act is now; whether it be changing your outdoor lighting habits or working with local elected officials to change policy, we can all make a change. Listed below are helpful resources and guides that can be used to understand better the problem and how to get involved in our community. Thank you for taking time out of your day to become the best environmental steward you can be!
Resources:
Below, you will find many helpful resources to further your education on light pollution and the Dark Sky movement.
How to get involved:
There are tons of ways to get involved to help fight light pollution, whether it be by attending an event, writing a letter to your elected official, or just by making conscious decisions about your lighting practices. Below, you will find some helpful links to find out more about how you can get involved, and make sure to follow EEC as we continue our campaign of fighting light pollution!