Founded by Senator Gaylord Nelson in 1970, Earth Day has become an annual opportunity for people around the world to reaffirm their commitment to protecting the planet we all call home. It’s a day for rallies, speeches, initiatives, and campaigns—all in support of immediate, expanded measures to reduce toxins, conserve natural resources, nurture wildlife and plant life, and generally be better stewards of the environment. And these things make our hearts sing! But we also believe that it’s important to take a step back from environmental action for a few moments, in order to meditate on the beautiful uniqueness of our world.
Barring any developments with the newly discovered Kepler-186f, Earth is the only known planet in the universe habitable to humans. And when you consider how tiny our apparently massive planet is compared to the immensity… of the universe, and how, with a fractional change in the speed of Earth’s orbit or axial rotation, all life would perish—oh, it takes your breath away! How fortunate we are that we have neither spiraled into the fiery Sun nor drifted away into the cold, dark vacuum of space.
Speaking of our Sun—merely one of 200-400 billion stars in the Milky Way—we owe a great deal to it as well. The process of photosynthesis springs to mind. Countless plants and trees, not to mention microscopic phytoplankton, rely on sunlight to live. Even humans, though technically we can live without sunlight, can experience mental distress and ill health when deprived of the Sun’s light and warmth. And if for some reason the photosynthesizing, oxygen-producing organisms died out, we would suffocate due to the abundance of carbon dioxide. Phytoplanktons alone are responsible for half of the oxygen produced by plant life on Earth.
Consider also the fact that, unlike other planets, Earth consists of over 70% water, a liquid second in importance only to blood. In ideal conditions, a healthy person can survive for 3-5 days without water. That’s not even a whole week! Some animals can live longer without water, but not all, and there are many that need water simply to breathe. Moreover, the constant evaporation and condensation of water creates rain to nourish the soil, hydrate organisms, and keep the oceans and rivers full.
Then there is the atmosphere itself, composed of 78% nitrogen, 21% oxygen, 0.03% carbon dioxide, and about 1% other gases (including water vapor). If oxygen levels increased and carbon dioxide levels decreased, or vice versa, or if the atmospheric pressure changed considerably, life could no longer exist on Earth. This is why scientists’ search for another habitable planet has so far been fruitless, because the composition of an atmosphere must be just right for us to survive without wearing special suits all the time.
Ironically, the further we explore space, the greater the odds become that we will find a sister Earth. True, Kepler-186f seems promising, as it could possess liquid water, but it may end up being another Venus or Mars. Nevertheless, of the potential billions of Earth-sized planets in the Milky Way, there might be none exactly like Earth. To find out, it would take us 100,000 years to travel across our own galaxy, and at least 3 billion years to reach the end of our universe—if it has an end, and if ours is the only one.
From these basic facts, it’s clear that we owe a great deal to our planet and must continue to preserve it as best we can. For not only is Earth the only home we have in the galaxy, it may be the only one in the entire realm of time and space! This Earth Day, we encourage you to alter your perspective. As environmentally conscious people, we sometimes literally “miss the forest for the trees” by focusing on what needs to be done to save the planet, while forgetting why it needs saving in the first place.
Remember the film “Silent Running”? The protagonist, Freeman Lowell, committed crimes against his fellow human beings in order to save a bit of Earth on that spaceship, drifting alone through desolate space. Though he intensely regretted his actions, he grieved more for the irreparable loss of what made Earth unique: green vegetation, animals, water, a specific composition of air, and above all the diverse beauty. In our search for other Earth-like planets and in our dedication to environmental stewardship here at home, let’s not be too busy to really savor the soil between our fingers, the birdsong in our ears, the breath in our lungs, and the cool water trickling down our throats.