Mainstream science article describing historical "mass extinction" event

Without even looking for it, I found this article on my Google news home page from a relatively mainstream (though pop) news source. The article drew a "causal link" between an increase in atmospheric carbon dioxide and a mass extinction event 250 million years ago. Though this is relatively distant history, and it may or may not be relevant to today's controversy over a runaway greenhouse effect, I still think it's interesting to stumble upon an article like this without even looking for it.