It isn't until the Earth is almost close enough to touch that our atmosphere becomes visible. It is this thin veil of gases, which in relative terms is no thicker than the dew on an apple, that makes life on this planet possible. Our atmosphere is as fragile as the breath that separates life from death, and equally as critical.
The paradox is that viewed from the planet's surface, the atmosphere seems like a limitless place. When you lie on your back on a clear sunny day, watching the clouds scud by, or stargaze on a clear night, it feels like you can literally see forever. But what we apparently fail to grasp is that so very little of what we're gazing up to is actually atmosphere.
While the Karman line, which is 100 kilometers above the Earth's surface, is often used as the boundary between the atmosphere and outer space, three quarters of our atmosphere's mass is within a mere 11 kilometers of the surface. In relative terms, that's the depth of our deepest ocean, or the distance we could comfortably walk in a couple of hours.
Our atmosphere is made up primarily of nitrogen (roughly 78 percent), oxygen (about 21 percent), argon, carbon dioxide (at an estimated 0.04 percent and rising) and other trace gases, including ozone.
This protective blanket of gases not only shields us from the sun's radiation, but also helps to warm the Earth and make it habitable. When the sun's rays hit the surface of the planet, some of them bounce back out into space. Our atmosphere captures the rest, much like panes of glass in a greenhouse. This so-called "greenhouse effect" isn't new or controversial, and until very recently, worked to keep the Earth's temperatures relatively stable and allowed life to flourish.
The problem is that thanks to human activity, we have altered the balance of gases in the atmosphere. This is at the heart of our looming ecological crisis. Increasing levels of carbon dioxide, primarily caused by the burning of fossil fuels, have thickened the layer of gases that regulates the Earth's temperature. It's as if we have literally wrapped the planet in a heavy blanket.
Ironically, most of the human activities that are adversely affecting the environment are things that we do to improve our own personal environments and make life more comfortable. Perhaps more to the point, we somehow feel entitled to all of these creature comforts.
"We live at a time when emotions and feelings count more than truth," writes noted scientist and author James Lovelock, "and there is a vast ignorance of science." Lovelock is the British scientist who originated the Gaia Hypothesis, the idea that all living and nonliving things are part of a complex interacting system that forms a single, living planet. As Lovelock points out, thanks to one part of that system, namely human beings, the entire system is in peril.
Part of the problem is that we don't humanize science. Science is something that we study. It's clear that what is needed is a greater scientific understanding of the Earth's living systems and our own roles and responsibilities within that system. Until we reach this level of understanding and learn to modify our actions accordingly, we place our planet and ourselves in peril.
"Unless we see the Earth as a planet that behaves as if it were alive, at least to the extent of regulating its climate and chemistry, we will lack the will to change our way of life and to understand that we have made it our greatest enemy," he wrote.
Only when we begin to think of the Earth as a living entity, unique in the known Universe, a bright and perfect blue jewel in space, will we truly begin to heal her wounds.
Earth Day is celebrated globally on April 22nd. This year pledge to make every day Earth Day. Check out Earth Day Canada’s excellent Ecoaction guides at www.ecoactionteams.ca or visit the main website at www.earthday.ca.
For more on the work of James Lovelock, including his latest book, “The Revenge of Gaia”, visit his official website.