Earth’s atmosphere now has more carbon dioxide in it than it has in millions — and possibly tens of millions — of years, ...

Breathe easy, for now. Scientists say our breathable air won't last forever. A new NASA-supported study warns that Earth's ...

And yet ideas for geoengineering – literally engineering ways to either lower carbon dioxide levels ... some of the sun's energy back to space, artificially cooling the Earth.

an older Earth with more CO2 could still be colder than the present because the sun was dimmer millions and billions of years ago, according to Alley. "The CO2 level at which the Earth is cold ...

Stock image of a sapling plant in the sun ... Stock graphic showing how photosynthesis works. It uses energy from sunlight to power a reaction between CO2 and water inside the plant, converting ...

Earth Day began 55 years ago on this date ... of heat-trapping greenhouse gases in the atmosphere, chiefly carbon dioxide, are now far higher than at any point during at least the last 800,000 ...

Climate 101 is a Mashable series that answers provoking and salient questions about Earth’s warming climate. The last time CO2 levels were as high as today, ocean waters drowned the lands where ...

Carbon dioxide (CO 2) is a greenhouse gas ... When energy from the Sun reaches the top of our atmosphere, most of it passes through to Earth's surface, where it is absorbed. Some of this energy is ...