The Earth at night. Credit: NASA
On Saturday, March 24th, between 8:30 and 9:30 pm local time, people around the globe will shut off their lights to participate in Earth Hour. The idea behind it is to “switch off lights and make noise for the Earth,” to highlight climate change and other challenges facing our fragile planet.
By using “light” for centerpiece this event, the organizers have picked something that represents both a problem and a potential solution for some the world’s most pressing issues.
For tips on improving outdoor lighting near year, see these helpful infographics from the city of Fort Collins. Credit: City of Fort Collins
For example, we are burning through finite fossil fuels that contributed to Earth’s warming in the quest to generate electricity, which powers our light bulbs and other forms of illumination. Moreover, much of the light that is created is underutilized and irresponsibly wasted through “light pollution.” Poorly designed lighting not only erases the beauty of the night sky, it squanders an enormous amount of energy.
Light defines our modern cities in many ways, as seen here in this photograph of Salt Lake City, Utah taken from astronauts about the International Space Station. Credit: NASA/Johnson Space Center
This statistic from the International Dark-Sky Association underscores just how much we waste in the pursuit of light: “In an average year in the U.S. alone, outdoor lighting uses about 120 terawatt-hours of energy, mostly to illuminate streets and parking lots. That’s enough energy to meet New York City’s total electricity needs for two years!”
Light, however, is important and artificial forms of it can lead to advances in health, security, productivity, and much more. By mindfully harnessing the power of light in its many forms, we can make the world a better place. While we often don’t think of light in this way, it comes in many forms from radio waves and infrared through X-rays and gamma rays. These various types of light make communication, medical imaging, information technology and much more possible.
Solar panels allow us to harness some of the vast energy that is provided to us every day from the Sun. Many people consider solar power as one of the most promising sources of renewable energy. Credit: Dennis Schroeder/NREL
While there are countless ways we use light throughout our day, perhaps the most important role that light might play for the future of our planet is the harnessing of its energy. Even with the growing human population, the Sun still outputs far more energy every year than the world consumes. Photovoltaic cells in today’s solar panels convert light from he Sun into electricity using semiconducting material such as silicon.
There are many hurdles that remain in order for solar power (and other renewable forms of energy) to take over from fossil fuels, but those challenges are not insurmountable. By increasing efficiency and storage capabilities and lowering costs and access, we could make solar power a viable source of clean energy for much, if not all, of the planet. If we consume less, think creatively, and invest wisely, there is no telling what we can achieve and light might help show us the way.
Behind the glow of an active volcano, the beautiful starry skies can be seen from a dark site in Hawaii. Unfortunately, light pollution from poorly designed and inefficient lighting is taking away these wonderful cosmic views from most people. Light pollution is so common only a handful of the very brightest stars can be seen from the ground in most urban and suburban environments. Credit: Rogelio Bernal Andreo/DeepSkyColors.com/Ciel et Espace
Megan Watzke and Kim Arcand are so fascinated with light that they wrote an entire book on it. “Light: The Visible Spectrum and Beyond” is available via online retailers and many independent bookstores. More on this and their other popular science books can be found at http://arcandwatzke.com/books