The Natural Greenhouse Effect:
Earth’s atmosphere is ninety-nine percent nitrogen and oxygen. The remaining one percent includes water vapor (H20), carbon dioxide (C02), and methane (CH4). These trace gases act as an insulating blanket, trapping some of the heat trying to radiate away from the planet. As in a garden greenhouse, this warmth remains within the atmosphere. Without this protective blanket, Earth’s surface would be almost sixty degrees colder.
“We should be very grateful for the natural greenhouse effect because Earth is some 60 degrees Fahrenheit warmer than it would be without it. It has made Earth the water planet, the blue planet, instead of just another white snowball in orbit around the sun.”
– Henry Pollack, geophysicist and author of A World Without Ice, 2009.