Light Pollution and Climate Change
A thick blanket of brown gray smoke settled over our neighborhood. It covered the entire front range of the Rocky Mountains and spread east over Denver on its way to Chicago, Pittsburgh, and the east coast.
Photo: BLM
About 50 miles north, my brother-in-law and his wife were evacuating, leaving their home in a state of uncertainty and anxiousness. Their small town on the eastern edge of Rocky Mountain National Park was surrounded on three sides by wildfire. The closest, aptly named the East Troublesome Fire, had started a few days earlier near their sister community on the west side of the park. In one alarming night it exploded, quadrupling in size. On the evening of Wednesday, October 21, the fire was 30,000 acres in size. That night, the winds kicked up and by the next morning the fire had devastated an area of more than 125,000 acres. It blew into Rocky Mountain National Park, over the continental divide, and became the second largest fire in Colorado history, only slightly smaller than the Cameron Peak fire which was still burning a short distance to the north*. Now, the troublesome fire was threatening Estes Park and forcing evacuations.
About six weeks earlier, we had our own scare. A fire broke out on Elephant Butte, about five miles from our home in Evergreen. It started small and quickly grew to fifty acres. Over a thousand of our neighbors were evacuated as the fire burned just uphill from their homes. Fortunately, due in part to cooler weather and some welcome humidity, it was brought under control after a few tense days. But, seeing the thick dark columns of smoke and watching the helicopters fill their tanks with water from Evergreen Lake, created a palpable sense of dread and helplessness in our little community.
Moonrise through smoke-filled skies above Denver - September 2020
They told us this would happen. Since I first heard about the changing climate back in the 1990s, scientists have been warning us that fire season would be longer and more intense. As bad as it was in Colorado, other states like California, Oregon, and Washington fared even worse.
As an environmental professional, I’ve had people ask me incredulously, “Why worry about the night sky and light pollution when civilization faces an existential threat from climate change?” I’ve given this question a lot of thought. Shouldn’t I be focusing my efforts and energy on the most significant environmental crisis of our time? It’s a valid question, but not surprisingly, it seems that there are important connections between the two. John Muir said that in nature "when we try to pick out anything by itself, we find it hitched to everything else in the Universe” As it turns out, light pollution is hitched to global climate change in important and compelling ways, and protecting the night sky is paramount to avoiding worst-case climate scenarios.
Lighting is one of the biggest contributors to energy consumption, accounting for almost one-fifth of the world's electricity use and generating nearly 2 billion tons of carbon a year. That’s equivalent to nearly three-quarters of the carbon emissions from all the cars and light trucks in the world. Improve lighting efficiency and reduce wasted light and you reduce greenhouse gas emissions (GHG).
Thankfully, a new technology has become available for wide-spread use in the past few years that is up to 90 percent more efficient than traditional lighting. Back in 1962, a General Electric employee named Nick Holonyak developed the first light-emitting diode (LED) that generated light in the visible part of the spectrum. From that first red LED, the technology developed and evolved, until finally, in the early 1990s, Isamu Akasaki, Hiroshi Amano and Shuji Nakamura created the first blue LED. That blue LED allowed lighting manufacturers to create high-efficiency white light, a major advance that earned the three inventors the Nobel Prize for physics in 2014. LEDs are a game-changer for lighting and a key step in reducing greenhouse gas emissions.
You may have heard that LEDs increase sky glow, harm wildlife, and have deleterious effects on human health. Generally, this is true, but in reality the relationship is a bit more complicated. There are ways to realize the energy efficiencies of LEDs while minimizing their negative effects. These practices are featured in the Five Principles for Responsible Outdoor Lighting, jointly developed by the International Dark Sky Association (IDA) and the Illuminating Engineering Society (IES). (Look for future blog posts on these principles!)
Source: International Dark Sky Association See: https://www.darksky.org/joining-forces-to-protect-the-night-from-light-pollution/
If every home in the country switched over to LEDs at once, we’d save an estimated 38 million tons of carbon dioxide emissions a year. That’s equal to the emissions from about seven million cars. If everyone switched to LEDs while also practicing the methods for minimizing light pollution found in the Five Principles, the energy savings and reductions in GHG emissions would be even more substantial.
Apocalyptic may be an overused word these days, but as I watched the smoke envelop my neighborhood, few other sentiments came to mind. I paced on my deck as the slurry bombers flew into the smoky skies and helicopters obliterated the early morning tranquility of Evergreen Lake. It’s not that this particular fire was a threat to me or my family, but the flames and smoke were a constant reminder that a careless toss of a cigarette butt, an unattended BBQ grill, or an errant lightning strike closer to home could spell disaster. Our nerves, like the surrounding forests were nearing a flashpoint. The next day, as my wife and I left the neighborhood for a trip to the local coffee shop and bakery, we saw something that stopped us in our tracks. On the hillside to the south of Turkey Creek, a couple of miles away, maybe less, a column of smoke rose above the forest. The forecast called for high winds by mid-afternoon. We pulled over and watched it for a few minutes. We had to call it in. After a few tense minutes, the dispatch for Evergreen Fire and Rescue assured us that a landowner in that area was doing some logging, and what we were seeing was likely exhaust from heavy machinery. My wife and I looked at each other. We started to breathe again. This is reality on the urban-wildland interface. Driven by our changing climate, the threat of wildfires is constant. The stress is another thick dark cloud that hangs over our neighborhood.
Solutions to climate change need to be multifaceted, and a transition to effective and efficient lighting will play a key role in mitigating the effects of climate change. Thankfully, reducing light pollution also improves and preserves our night sky, protects wildlife, and helps maintain our health. Take a look at your home and your neighborhood, replace your older lights with LEDs, follow the Five Principles for Responsible Lighting, and do your part to prevent and minimize the impacts from climate change.
*The third largest fire in Colorado history also started in 2020. The Pine Gulch Fire burned 139,007 acres north of Grand Junction from the end of July until mid September.