Greenhouse Earth: Methane powered runaway global warming

0 Comments | AFP, September, 2007

PARIS (AFP) — Methane released from wetlands turned the Earth into a hothouse 55 million years ago, according to research released Wednesday that could shed light on a worrying aspect of today's climate-change crisis.

Scientists have long sought to understand the triggers for an extraordinary warming episode called the Palaeocene-Eocene Thermal Maximum (PETM), which occurred about 10 million years after the twilight of the dinosaurs.

Earth's surface warmed by at least five degrees Celsius (nine degrees Fahrenheit) in just a few hundred or a few thousand years. The Arctic Ocean was at 23 degrees Celsius (73 degrees Fahrenheit) -- about the same as a tepid bath -- before the planet eventually cooled.

Richard Pancost, a researcher at Britain's University of...