October 23, 2023
City of Los Altos
1 N San Antonio Rd,
Los Altos, CA 94022
Dear Mayor Meadows and Los Altos City Councilmembers,
The Santa Clara Valley Audubon Society and the Sierra Club Loma Prieta Chapter submit this letter for your consideration. Together, our organizations represent tens of thousands of members in Santa Clara County, including Los Altos. Our members care deeply about natural ecosystems, wildlife, and protecting our environment, including the night sky. In the past few years we have focused on one of the most harmful disruptors to the environment and to human health: light pollution. We are pleased to see Item 6 on your 10/24 agenda (Dark Skies Discussion) and hope the City of Los Altos proceeds to develop a dark sky ordinance and augment it with policies and standards for bird safe design of buildings and structures in Los Altos.
- We wish to offer the following observations:
- Scientific evidence that Artificial Light at Night (ALAN) is harmful to ecological processes, biology, behavior and health in all living things (including humans), and to scientific exploration and advancement is indisputable1. Lighting in the blue, cold part of the spectrum is especially damaging to life. We appreciate the staff report attention to the importance of aesthetic and energy-conservation aspects of light pollution. We wish to emphasize the pervasive impacts of lighting on seasonal and circadian rhythms in plants and animals and the resulting disruptions to biological phenomena (migration, attraction or aversion by animals, reproduction in most animals) and even human health. Outdoor lighting has been linked to cancers, diabetes, impaired mental health and more.
- In addition to the City of Cupertino, which has already adopted a Bird Safe and Dark Sky ordinance, several cities in our region are currently in the process of drafting Dark Sky ordinances, including Palo Alto, Mountain View, Brisbane, Santa Clara County, and likely Sunnyvale. These ordinances aim to reduce light pollution and improve ecological, environmental and human health by regulating outdoor lighting in all private properties, with some considerations to the type of development and its location.
- Bird Safe Design regulations, aimed to protect birds from collision with glass and other structures, are being implemented in many cities in our region, including San Francisco, San Jose, Cupertino, Sunnyvale and Mountain View. Palo Alto is currently developing an ordinance. Los Altos, a city where residents appreciate nature, should join this effort to protect our birds from collision.
- Wherever asked, residents showed awareness to the loss of darkness at night and were supportive of regulations aimed to reduce light pollution. The community members are even more supportive when educated about the implications of Artificial Light At Night to environmental and human health. People are also supportive of bird safe design regulations that aim to reduce the hazards that glass and other elements of our built environment pose to birds.
- The Analysis provided in the Staff Report covers most of the state-of-art guidance, but we would like to offer additional recommendations:
- LED technology has advanced, and warmer-light fixtures are available. We recommend a maximum Correlated Color Temperature of 2700 Kelvin or less. This reduces the harsh and harmful blue light emitted by light fixtures.
- Overlighting is currently an issue in most of our communities, and it is one of the reasons residents generally support regulation. It is therefore important to address existing non-compliant lighting, as has been done in Malibu and proposed in Brisbane. Non-compliant lighting is allowed a grace period to correct the problem.
- The Staff report raises the following Policy Questions for Council Consideration.
- Does the City Council wish to proceed with the development of a local Dark Skies Ordinance?
- Please respond ‘yes’!
- Which Main Principles Should be Included?
- Please include the International Dark Sky Association Five Principles for Responsible Outdoor Lighting (Useful, Targeted, Low Level, Controlled, Warmer color. See note at end of letter for explanation.)
- In addition, please expand the scope to include bird safe design policies and standards.
- What Applicability Should be Required?
Please apply to,- Outdoor lighting on all private properties, including existing lighting, and
- Indoor lighting in office/commercial buildings,
- Buildings, structures and architectural elements that pose hazards to birds.
- The Sierra Club Loma Prieta Chapter and the Santa Clara Valley Audubon Society have developed a model Dark Sky ordinance and a compilation of Bird Safety standards, which we are happy to share with Los Altos Staff.
We look forward to supporting Dark Sky and Bird Safety protections in Los Altos.
Respectfully,
Shani Kleinhaus, Ph.D.
Environmental Advocate
Santa Clara Valley Audubon Society
James Eggers,
Chapter Director
Sierra Club Loma Prieta Chapter
https://darksky.org/resources/guides-and-how-tos/lighting-principles/:
- Useful: Use light only if it is needed. All light should have a clear purpose. Consider how the use of light will impact the area, including wildlife and their habitats.
- Targeted: Direct light so it falls only where it is needed Use shielding and careful aiming to target the direction of the light beam so that it points downward and does not spill beyond where it is needed.
- Low Level: Light should be no brighter than necessary Use the lowest light level required. Be mindful of surface conditions, as some surfaces may reflect more light into the night sky than intended.
- Controlled: Use light only when it is needed. Use controls such as timers or motion detectors to ensure that light is available when it is needed, dimmed when possible, and turned off when not needed.
- Color: Use warmer color lights where possible: Limit the amount of shorter wavelength (blue- violet) light to the least amount needed.