Access

News and Views

Nature 454, 41-42 (3 July 2008) | doi:10.1038/454041a; Published online 2 July 2008

Open Innovation Challenges

naturejobs

Atmospheric chemistry: Her dark materials

Kevin Zahnle1

Top

A glitch in the history of sulphur isotopes could imply that methane emitted by the ancient biosphere created a high-altitude photochemical smog, which governed the climate in a distinctly Gaian way.

Free oxygen became abundant in Earth's atmosphere around 2.3 billion years ago, a change that was preceded or accompanied by at least three major ice ages.

  1. Kevin Zahnle is at the NASA Ames Research Center, Moffett Field, California 94035, USA.
    Email: kevin.j.zahnle@nasa.gov

MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.