An Astronomer’s View of Street Lighting

Image of United States and light pollution across the country.
Photo Credit: is a mapping application that displays VIIRS/DMSP/World Atlas overlays and the user measurements overlay over Microsoft Bing base layers (road and hybrid Bing maps).

An Astronomer’s View of Street Lighting

By Lawrence L. Faltz MD, President, Westchester Amateur Astronomers

When the Northridge earthquake cut power in Los Angeles in January 1994, the Griffith Observatory received phone calls from concerned citizens asking about a mysterious cloud overhead that they had never seen before. The Milky Way, our galaxy, had probably not been visible from downtown LA for half a century.

It’s estimated that more than two-thirds of the people in the world cannot see the Milky Way from their homes. We light up our environment for safety, to allow us to move about at night, and to decorate our homes and businesses. But this light is also obliterating the stars–a source of inspiration and information for diverse cultures across the centuries.

Light pollution doesn’t just wash out the glories of the night sky and frustrate amateur astronomers. It wastes energy and money. Poor lighting design creates glare that actually makes it difficult to see well at night. Misdirected light crosses property lines and intrudes into homes, disturbing sleep. Hundreds of studies have documented the adverse effects of light pollution on the environment. It has devastating impact on some animal behaviors. More than 1,600 investigations into its impact on human health have been published. It may be a carcinogen. The American Medical Association is sufficiently concerned to have voted to “support light pollution reduction efforts and glare reduction efforts” and to “support efforts to ensure all future streetlights be of a fully shielded design or similar non-glare design to improve the safety of our roadways.”

Photo Credit: Updated light pollution map of lower New York State.

Municipalities all over the United States, including towns in Westchester, are replacing their older streetlights with brighter LED streetlamps. The main reason is economic: LED streetlamps use much less power and have very long lives, reducing costs. New York City is replacing a quarter of a million street lamps and each year expects to save $6 million in energy costs and $8 million in maintenance. Another positive factor is that these fixtures are better shielded than the old “cobra head” sodium vapor lamps, projecting more of the light where it’s needed and not uselessly up to the sky. However, while shielding is better than before, it’s not as good as it could be. New York City’s LED streetlamps still project 5% of the light upward and up to 20% into the “glare zone” at or above 80 degrees. Many municipalities are installing similar “semi-cutoff” street lamps.

In addition, most of the fixtures installed to date use LED’s that emit light that is enriched in the blue part of the spectrum. Blue-rich LEDs produce three times as much skyglow as the older lights because blue light scatters much more efficiently than light in the “warmer” (yellow) part of the spectrum, a phenomenon known as “Rayleigh scattering.” The daytime sky is blue because our atmosphere scatters blue light in the sun’s spectrum more than other colors. Blue-rich light also causes more glare, poses greater difficulties for older eyes, has more damaging ecological impacts, and more readily disrupts human circadian rhythms. LED’s that have a warmer color temperature and produce nearly the same amount of light per watt consumed as blue-rich LEDs are now available for outdoor use.

We may have to wait until the end of the 15-year life span of new LED street lamps to try to get them replaced with warmer lamps. If your town is still in the process of acquiring and installing LED street lamps, ask it to use the warmer, more ecologically and medically friendly bulbs in fully-shielded fixtures.

A source of light pollution you can control is your own home. Replace decorative lighting that throws light upwards where it’s not needed with fixtures that direct the light downward. Use warm LED bulbs. Turn off outside lights when they’re not needed. Ask your neighbors and businesses you frequent to do the same.

For more information, check out, the web site of the International Dark-Sky Association.

Resources for further reading:


Lawrence L. Faltz MD, President, Westchester Amateur Astronomers

Dr. Faltz is a life-long amateur astronomer. He was Chief Medical Officer of Phelps Memorial Hospital Center from 1994 to 2017 and is Clinical Professor of Medicine at New York Medical College.

Eagles and the Hudson

By Kate Munz, Member Relations Coordinator

Photo Credit: NYTimes on 5th Annual Eaglefest

In honor of Teatown’s EagleFest, we wanted to highlight the star of the yearly event, the bald eagle.

In the Hudson Valley we are very lucky to share space each season with this majestic, and nationally famous neighbor. While can see bald eagles yearly now, this was not always the case.

Before the 1900s, bald eagle populations in New York were plentiful, as many as 80 nesting sites according to the State Department of Environmental Conservation. But by 1976, only one pair of eaglets remained. Environmental groups citied pesticides, specifically DDT, for the reduced numbers. During that year, the state began its Bald Eagle Restoration Project as an attempt to bring back the population.

Today, approximately 500 bald eagles winter in New York. The eagles migrate to this region, usually arriving in December, as waters freeze in Canada and Nova Scotia. Eagle concentrations peak in January and February; heading back to their nests by mid-March.

We’ve seen the return of our eagles due to clean air and water, ample food supply, and largely undisturbed stands of trees – as these are important elements that support breeding pairs of eagles. It is therefore essential that we maintain this important habitat. Together we can work towards open space preservation and watershed protection.

Learn more about what you can do by visiting this page:


Getting the Facts on the AIM and Biodiversity

The Algonquin Pipeline and the Effects of ROW: A Summary of the Hudsonia, Ltd. Assessment

By Kate Munz, Member Relations Coordinator

Hudsonia Ltd., a non-advocacy not-for-profit institute for research, educates and assists decision makers in the environmental sciences by providing objective, accurate, up-to-date, site specific information – and Hudsonia has conducted studies of the proposed Algonquin Pipeline expansion.

Early this year, Hudsonia Ltd.’s Executive Director, Dr. Erik Kiviat, prepared a “Preliminary Biodiversity Assessment of the Algonquin Gas Pipeline at Reynolds Hill and Blue Mountain Reservation, City of Peekskill and Town of Cortlandt, Westchester County, New York.” The scope of the assessment was to examine the possible risks to biodiversity as related to the proposed gas pipeline expansion, which is of the utmost concern as the trajectory goes through Blue Mountain Reservation, a county-owned park.

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A Look Into Our Past – “Ward Pound Ridge Reservation gets Biodiversity Preserves”

This is the seventh installment of our “A Look into Our Past” Series, honoring the past five decades of environmental work in Westchester County. This series revisits some of our best accomplishments by featuring past articles from our original publication “Westchester Environment.” 

“Westchester Environment” – Vol. 97 No. 3 – March & April 1997

4059_001(1)Ward Pound Ridge Reservation gets Biodiversity Preserves

By Gudrun LeLash, FCWC Executive Director 1997

For several years FCWC studied how to protect biodiversity and habitat in Westchester. It received funds for computer hard and software for data gathering and public education through the good offices of State Assemblyman Richard Brodsky. Preexisting and new data were collected.

In 1994, under the leadership of Michael Klemens, herpetologist at the Wildlife Conservation Society, a cooperative effort among the Westchester County Parks and Planning Departments, WCS and FCWC began in county parks – land already protected and accessible to us. Since it is public land, we felt we might be able to influence the management and protection of sensitive natural areas.

After three years of field study, two areas of Ward Pound Ridge Reservation, nearly 1,500 acres, were declared Biodiversity Preserves by the Parks Board. The land was deemed of significant value, and biodiversity protection will be a major consideration in future plans for the park. Although not as strongly worded as we would have liked, it is, however, a beginning in the effort to secure the species and habitat diversity.

Our efforts notwithstanding, safeguarding Westchester’s natural resources will still depend on interested public citizens 50 or 100 years hence. If the Reservation were developed outside the Biodiversity Preserves, these protected areas would be at risk. For that matter, if the rural neighborhood bordering the Reservation were paved up to its boundary, the preserves would be jeopardized.

As they say, in this democracy, educated citizens and eternal vigilance are vital. What we have achieved, however, is a heightened sense of awareness about the species and habitats that exist within Ward Pound Ridge Reservation and elsewhere in our region.

A Look Into Our Past – Westchester Environment, “New York State Breeding Bird Atlas”

This is the fifth installment of our “A Look into Our Past” Series, honoring the past five decades of work done by Federated Conservationists of Westchester County. This series revisits some of our best accomplishments by featuring past articles from our original publication “Westchester Environment.” 

In this post we would like to welcome spring and the start of the birding season with a piece on the first New York State Breeding Bird Atlas. This article, written by Berna Weissman our then Treasurer, delves into the planning and work behind the Breeding Bird Atlas Project 1980, which culminated in a published Atlas. In December 2008 a “Second Atlas of Breeding Birds in New York State” was released with updated information and public Google Earth datasets. Details on this “Second Atlas in Breeding Birds in New York State” can be found here:

“Westchester Environment” – Vol. 4 No. 3 – April & May 1982

A Look Into the PastNew York State Breeding Bird Atlas: a work a scientific significance

By Berna Weissman, FCWC Treasurer (Excerpt from)

Even in New York, endowed with a long history of ornithology and the current activity of a large number of professional and amateur observers, the precise distribution of the more than 200 species of birds which breed here is imperfectly known. Previous publications have had to rely on scattered studies of single species and random observations. The Federation of New York State Bird Clubs, seeking to fill this gap, launched the Breeding Bird Atlas Project in 1980, in cooperation with the New York State Department of Environmental Conservation, National Audubon Society, Cornell University Laboratory of Ornithology and New York State Museum.

To accomplish the enormous task of mapping the distribution of all breeding birds, the entire state has been divided into approximately 5000 blocks of 25 square kilometers, each to be surveyed for the species breeding within it. The field work, which will last for five years, is being done by volunteers who, by visiting all the habitats within a block at various times throughout the breeding season, locate and identify birds, make observations of their behavior and code them as possible, probably, or confirmed breeders according to a list of established criteria. Publication of the Atlas is expected in the latter half of this decade.

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Don’t give parkland for pipeline expansion

Written by Carole Griffiths, Co-President of FCWC

(Photo: Joe Larese/The Journal News)
(Photo: Joe Larese/The Journal News)

Blue Mountain Reservation is a 1,538-acre county-run park in the northwest section of Westchester County. It features miles of trails and offers challenging hikes to the tops of two large peaks, Mt. Spitzenberg and Blue Mountain. The park is used heavily by the public.

There is also a natural gas pipeline running though the park. Spectra Energy is proposing to enlarge this 26-inch diameter pipeline, installed in the 1950s, to a massive 42-inch diameter, high-pressure (850 pounds per square inch) transmission pipeline. The construction would require an expanded work easement of up to 130 feet, 55 feet beyond its present 75-foot right of way.

Enlarging this pipeline and the expansion of the easements will have negative impacts on the park. There will be permanent destruction of trees and habitat for animals. New edges will be opened a few hundred feet into the forest on either side of the expansion, which will allow invasive species to further infiltrate the park.

The route of the proposed Algonquin pipeline expansion. (Photo: Spectra Energy)

Important habitats are close to or adjacent to the proposed pipeline. These include a sizable stand of hemlock trees (mostly dead in our region), what may be an original wetland and a pond that is home to amphibians, turtles, fish and dragonflies. All are essential to preserve intact. In particular, the pond will also be affected by silt and other contaminates, killing eggs laid in the spring.

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The Future of Westchester County Parks Wrap-up

Future of WC Parks_1On January 23rd, FCWC and the Greenburgh Nature Center hosted a roundtable discussion on the future of Westchester’s parks, sanctuaries, and nature centers.

An amazing success – about 50 individuals concerned about preserving natural habitat and wildlife in Westchester, participated in the discussion about the major resources at the various parks and preserves, the problems in preserving habitat and biodiversity and solutions that are planned or now being implemented. We were particularly interested in identifying the resilience needed for the challenges of climate change’s impacts on Westchester County’s open spaces.

At the beginning of the event, participants were asked to identify major resources, and those that were of importance to protect on properties that they managed, volunteered with, or recreated on. Next, they came up with top problems found on those properties, and many common problems emerged such as invasive species, deer, and the proper way to manage various habitats. Discussion then moved to actions and solutions that are currently being implemented to address these problems, and what plans/if any are on the table to adapt and or recover from impacts of climate change.

One overarching theme that was present amongst participants was there was a lot of knowledge, skills and talent in the room, and that we need to tap into the collective knowledge so each area and group is not continuously re-inventing the wheel for their properties.

As follow up for this roundtable discussion, FCWC has created a Westchester Open Space Google Group where members will be able to start a discussion, pose a question, or make an announcement concerning management or preservation of any park, sanctuary, nature center or open space in Westchester County. This Google Group will be helpful to organizations to collaborate to manage and preserve Westchester’s open space resources. We will be curating a list of resource and reference links on resource management that will be available on our website,, at a future date. We will also organize future workshops and conferences on natural areas with experts to address issues raised by this workshop. Please stay tuned for details about these initiatives as we move forward with them.

We want to thank everyone who came out and made this conversation so fruitful, and hope to play an integral part of protecting and improving Westchester County’s natural areas going forward.

To see further updates from this past workshop and the more to come, check back to FCWC’s events page.