Today's Coming Crisis Movie

Saturday, July 23, 2011

Mass Extinction Easier to Trigger Than Thought

The cataclysmic extinctions that scoured Earth 200 million years ago might have been easier to trigger than expected, with potentially troubling contemporary implications.

Rather than 600,000 years of volcanic activity choking Earth’s atmosphere with carbon dioxide, just a few thousand years apparently sufficed to raise ocean temperatures so potent greenhouse gases trapped in seafloor mud came bubbling up.

Much of everything alive on Earth was soon wiped out. Another half-million years of vulcanism were just icing on the cake. The immediate question: What lessons, if any, can be drawn?

“Scientists have been worried about the current release of methane from seafloors. What this study shows is that it already happened in the past,” said paleoecologist Micha Ruhl of Utrecht University, whose findings are published July 21 in Science. “It could happen again. It’s only the boundary conditions that we don’t know.”

In what scientists call the end-Triassic mass extinction, at least half of all living species simply disappear from the fossil record. The die-off didn’t merely cause ecological disruption. It was so sudden and profound that planetary chemical cycles went haywire for the next several million years. (more)