04-19-21 | Feature

The International Dark-Sky Association

A Conversation with Executive Director Ruskin Hartley
by Aaron Schmok, LASN

In 2016, Grand Canyon National Park began a program to remove thousands of lighting fixtures around the park to eliminate light pollution. Their efforts resulted in 5,000 fixtures being replaced with IDA compliant alternatives in 2019. Photo by Royce Bair
The International Dark-Sky Association (IDA) is a nonprofit organization and the recognized authority on light pollution. They are the leading association on combating light pollution worldwide through educating policymakers and the public about night sky conservation and promoting environmentally responsible outdoor lighting.
Capitol Reef National Park spans 242,000 acres in southern central Utah. The park underwent a multi-year program dedicated to educate park staff and visitors and to adopt strong lighting practices to preserve the night sky. Capitol Reef was recognized as a IDA Park in 2015. Photo by Royce Bair
Artificial lighting on sea turtle nesting beaches has been shown to repel adult females searching for nest sites and prevent hatchlings from safely reaching the ocean by drawing them toward the light instead of the sea.
This illustration is a visual guide that depicts the differences between what IDA considers unacceptable, unshielded light fixtures and fully shielded fixtures that minimize skyglow, glare and light trespass. The narrow profile wall mounted luminaire from Ligman is an example of an IDA certified fixture.
This illustration is a visual guide that depicts the differences between what IDA considers unacceptable, unshielded light fixtures and fully shielded fixtures that minimize skyglow, glare and light trespass. The narrow profile wall mounted luminaire from Ligman is an example of an IDA certified fixture.
Arches National Park in Moab, Utah was recognized as a National Dark Sky Park in July 2019. Park rangers in Arches have led educational astronomy demonstrations and events since 2012. Their Dark Sky certification has helped support these programs and their commitment to maintain an unpolluted night. Photo by Bettymaya Foott
As a proxy to wavelength measurements, many people use correlated color temperature, which is measured in Kelvin, for the spectrum of light. The lower the Kelvin number the more benign the fixture will be. There are many fixtures with under 3000 Kelvin bulbs and many are coming onto the market with under 2200 Kelvin and many of those have much fewer blue light emissions. IDA recommends using light sources with the least short wavelengths emmissions as possible.

About the Association
The International Dark-Sky Association (IDA) was founded 32 years ago in Tucson, AZ where they currently have a small professional staff. The international organization relies on their supporters and network of advocates around the world, having people active in 50 countries around the world in every inhabited continent, to help raise awareness about light pollution. The association has found success through providing tools and resources to help combat the issue of light pollution, and by sharing success stories about where people have incorporated effective lighting to make connections so that people don't feel so alone in their efforts.

IDA believes in recognizing best practices with one of their signature programs being International Dark-Sky Places Program. It's been around for 20 years now taking place in 174 locations around the world protecting more than 110,000 square kilometers of land. Each of these areas have common characteristics; They are places where, being community parks or large landscapes that value dark skies. Through this program the association is going to take all the steps they can to use light responsibly while also educating people and inform people about the value of natural darkness and what responsible lighting can do.

The Light Pollution Problem
One of the most common issues is the lack of awareness about light pollution. Despite that, 83% around the world and 90% of the US and Europe live under light polluted skies and over the last decade or so light pollution has been growing about twice the rate of the population growth, and its impacting almost everything, millions of migrating birds are dying. It is one of the leading causes of the decline of insects around the world, and the wasted light is contributing to climate change. Additionally, results in billions of dollars wasted in energy bills every year and has a long negative impact on human health.


Humans have an interesting relationship with light and are drawn to light. Having grown up and evolved under an environment of bright sunshine in the day and dark nights and that's what humankind has adapted to. Early forms of civilization were drawn to the warmth of the fires as a place of safety and a place of coming together and community. What's happened over the last 100 years is that every time there is a new technological development with the ability to light the night has led to the capacity to put out more light at lower cost, and this has been seen time and time again. More recently, in the past 10-12 years there has been a revolution of LEDs, creating the ability to put bright white light anywhere at extraordinarily low cost. Over the past decade, IDA has found that a lot of that light has been mis-applied and is, therefore, very damaging to the environment. The fact that it is so cheap has people taking those cost savings and putting even more light out there. This perception that more light makes people safe is a false narrative.

"What I've learned during my time with IDA is that once you see a bad light, you see them everywhere, so most people aren't aware that more light doesn't make us safe, better light makes us safe. Those are some of the narratives that we have to break down, and really expose people to," explained Ruskin Hartley, IDA executive director. "IDA's approach has never been about turning off all the lights, it's about better lighting for society. Better lighting and more effective lighting, so that you can light the ground and light the path ahead and still have a dark sky which is a symbol of many aspects of sustainable living." IDA's Fixture Seal of Approval program certifies luminaires against dark sky design criteria and makes it easy for consumers to find lights that are functional, and help protect the night from light pollution.

Success Stories
A couple large national parks in the United Kingdom have become Dark Sky reserves which is special because they are living landscapes. Similarly, there are communities that are taking steps to change out their lights and shine there lights down and keep it warm as they value the sense of place that it creates. There are also many parks in the United States that have found success with preserving dak skies. One of the more iconic ones is the Grand Canyon where they changed out about 5,000 lights to get recognized as an International Dark Sky Park.

One of the key aspects about IDA's work is about keeping dark places dark. For example, areas like the heart of Death Valley where certain spots within the valley where lights from Las Vegas are visible on the horizon. More work needs to be done in and with these communities, so they can use light more effectively and helping them understand that it's not a tradeoff between lighting the city for people to move around at night and having no light. An example of this is in Tucson who went through a street lighting conversion, as they wanted to update their streetlights to meet new climate change goals so they could reduce energy use. They updated their system form a high-pressure sodium lights to LED light, and with careful use of shielding, controls, using the right illumination level, and choosing the appropriate fixtures. They were able to reduce the total number of lumens that they used across the city by 60% and reduced light pollution by 7% and save $2.3 million a year. "Tucson is not a small city. It has a population of about half a million people. If we can do it here, we can do it everywhere. More and more what we are learning is that, while shielding is critical, proper illumination levels are essential to reducing light pollution."

Choosing the Right Light / LEDs
The great thing about LEDs is their efficiency. They are controllable both in terms of the direction of the light, through the fixture, and the ability to put them on a dimmer being able to dim them to 10% or even 1%. One of the issues with the old fixtures is they would take a long time to warm up, so you couldn't turn them off or dim them. There are some inherent capabilities in solid state lighting LED technology that, when used well, can be part of the solution. Part of the challenge with LEDs is that most white LEDs are short wavelength blue LEDs with a coating that converts some of the light to longer wavelengths. If you look at the underlying spectrum, they retain a strong peak in the blue range. The problem with this is that those wavelengths are the most energetic. Most animals are attuned to it, so if you put white LEDs with blue light you will disrupt wildlife. IDA recommends using control and the proper spectrum of the light to minimize the amount of shortwave length emissions going into the environment.

From a landscape architecture perspective one of the growth areas in the lighting industry is outdoor lighting with low-voltage, landscape lighting. The same principles apply as IDA recommends shining them down, not up, but if they have to be aimed up, make sure they are put on a switch so it's not on all night and turn it on when you need it. While each of those bulbs might be relatively minor, if you add them up across a whole city or a whole neighborhood it starts to become a significant amount of light.

Lighting is not regulated in the same way as other environmental components. For instance, the United States has regulations for clean air and water, but there is no statute that sets the standards for what constitutes a clean night sky, so that's one of the challenges. In fact, at the state level, very few have any statutes on the books that deal with light pollution, so essentially the whole issue with light pollution has been pushed down to the local level. To effect change you have to talk to the city councils and supervisors.

"Our role is to support the movement around the world. It is clear that too much light in the wrong place, at the wrong time, is a real pollutant to be dealt with as any other environmental issue. We also recognize that every community is different. What works in one community might not work in another, so we want to honor those differences to unite towards the goal of reducing light pollution."


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