The sixth extinction Feb 12 2014
About 250 million years ago, Earth suffered its fifth (and worst) mass extinction event. Nearly seventy percent of land species disappeared. And they got off easy compared to marine species. Are we headed for another mass extinction on Earth? I'm not ready to break that news. But something unusual is definitely going on and extinction rates seem to be speeding up. Here's an interesting chat with Elizabeth Kolbert, author of The Sixth Extinction.
The worst mass extinction of all time came about 250 million years ago [the Permian-Triassic extinction event]. There's a pretty good consensus there that this was caused by a huge volcanic event that went on for a long time and released a lot of carbon-dioxide into the atmosphere. That is pretty ominous considering that we are releasing a lot of CO2 into the atmosphere and people increasingly are drawing parallels between the two events.