From “Hazy Shades of Life On Early Earth” (ScienceDaily, Mar. 18, 2012), we learn,
A ‘see-sawing’ atmosphere over 2.5 billion years ago preceded the oxygenation of our planet and the development of complex life on Earth, a new study has shown.
Research, led by experts at Newcastle University, UK, and published March 18 in the journal Nature Geoscience, reveals that Earth’s early atmosphere periodically flipped from a hydrocarbon-free state into a hydrocarbon-rich state similar to that of Saturn’s moon, Titan.
This switch between “organic haze” and a “haze-free” environment was the result of intense microbial activity and would have had a profound effect on the climate of Earth system.
The conditions which enabled the bi-stable organic haze to form permanently ended when the atmosphere became oxygenated some 100 million years after the sediments were laid down.
“What is most surprising about this study is that our data seems to indicate the atmospheric events were discrete in nature, flip-flopping between one stable state into another,” explains co-author Dr Farquhar.
Flip(flop)ing between one stable state and another? Sounds like design. Don’t tell anyone.