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Earth Hour Uses Darkness to Shed Light on the Environment

star filled night sky
photo by Tyler Hutchison

If there’s a silver lining to the worldwide COVID-19 pandemic, it’s that we are seeing clear evidence of the effect human activity has on the environment. Satellite images of major cities, before and during social distancing, show a near-disappearance of pollution as streets and highways sit abandoned.

For 13 years, the annual Earth Hour event has worked to offer a similar effect, a stark visual representation of how human habits change the face of the earth. On the last Saturday of each March, Earth Hour invites people to turn their lights off for one hour at 8:30 p.m. 

It’s a simple action, but when taken in large numbers, the result is a startling darkness, an abrupt end to the buzz of electricity and the constant glow of light bulbs.

When businesses, cities and universities join the effort, entire cityscapes have a completely different look and feel for the hour: a natural darkness and calm, as if humans had never interfered.

Earth Hour was started in 2007 by the World Wildlife Fund (WWF) in Sydney, Australia, where the iconic Harbour Bridge and Opera House were darkened along with the rest of the city for a full hour. The idea was to bring attention to environmental issues like climate change, deforestation and sustainable energy.

Since its start, the event has added numerous cities and engaged millions of people in more than 180 countries and territories. It has inspired important conversations at the grassroots level and beyond, as well as collective action to protect natural resources.

This year’s Earth Hour event will be on Saturday, March 28, at 8:30 p.m. If you plan to participate, let the WWF know so they can have an accurate headcount in the absence of in-person, crowd events. Here is a list of things you can do while the lights are out. Social distancing has probably given you lots of practice at some of these! (Also, check this list of 2020 participants to see which cities, businesses and universities have joined the movement, and consider asking yours to take part.)

An additional benefit of Earth Hour is the brief absence of light pollution, the disruptive effect man-made light sources can have on our perception of the night sky.

starry night
photo by Tyler Hutchison

Tyler Hutchison, a Richmond student and astrophotographer, is familiar with this phenomenon. Last year, he won a national award from The Astronomical League for a photo he snapped in the pre-dawn darkness on a deserted North Carolina beach.

“In Richmond, the stars are much dimmer so you really have to look for them,” he says. “At the beach, and anywhere else far from city lights, they’re extremely bright and impossible to miss. I think everyone, from the most experienced astronomers to the casually interested, should be able to have that experience.”

You can help fight light pollution with a citizen science project from Globe at Night. All you have to do is go out after sunset, let your eyes adjust to the darkness, and count the stars you can see in various constellations.

 Register here for complete instructions on how to collect and submit your data. The answers you give will help scientists track levels of light pollution and the effects these levels have.

If you’d like to venture beyond your own yard, you can sign up to “Adopt a Street” and measure sky brightness every mile or so along the road you choose.

Learn more about light pollution from NASA’s Night Sky Network, the International Dark Sky Association, and this interactive map.