See how much carbon your household appliances put into the atmosphere - and what you can do about it.

Three families try to cut their energy consumption to 80 percent of the average American family's.

Are your electronics drawing power from the grid when you think they're turned off? Take a quiz to find out.

See photographer Jodi Cobb's images of middle-class families, worlds apart, with very different carbon footprints.

Surface temperatures on Earth are warming at a pace that signals a decisive shift in the global climate.

From our 2007 story, "The Big Thaw," learn how you can shrink your carbon footprint.

Watch interviews with scientists, explorers, and other leading thinkers on climate change.

How much do you know about the effects of global warming? Take a quiz to find out.

Is recycling really better for the environment than burying or burning waste?

The American West was won by water management. What happens when there's no water left to manage?

The lands of perpetually frozen earth reveal the delicate rhythms of the planet. But will permafrost stay permanent?

World oil demand is surging as supplies approach their limits.