Nature World News: Early life on Earth may have survived some 2.8 billion years ago through an atmosphere equipped with reasonable amounts of carbon dioxide and just a dash of methane, a new study suggests.
The period, known as the Archean eon, was characterized in part by a Sun approximately 20 percent dimmer than today's.
Conducted by researchers at the University of Colorado, Boulder, the scientists point to the use of sophisticated three-dimensional climate models running for thousands of hours on the school's...