'/> Uncommon Hours: May 2013
Blogging on culture, politics, and the environment since 2008.

Sunday, May 19, 2013

Michael Brune: Earth "a paper-thin shield between life and the dark void of space"

The Overview Effect
Michael Brune
By Michael Brune, Executive Director of the Sierra Club 

Few of us will ever venture past the 60-mile boundary that separates Earth and outer space. If you do, though, you're likely to experience something known as "the overview effect" -- a cognitive shift in how you perceive our planet. Political boundaries disappear, and our atmosphere, which seemed like a boundless expanse of blue from the ground, is suddenly revealed to be a paper-thin shield between life and the dark void of space.

Last week, the fragility of that thin blue shield was underscored by the news that we've
reached a daily average of 400 parts per million (ppm) of carbon dioxide in our atmosphere. That's the highest level in at least 3 million years. In less than two centuries, we've increased atmospheric CO2 by 42 percent -- by burning fossil fuels, degrading our forests, and disturbing our soils. And it's still going up.