NPR: "the lesson is loud and clear for those who choose to hear it: increased concentrations of atmospheric CO2 acidify the oceans and kill marine life"

NPR.org » The Great Dying And Climate Change

In other words, a gigantic volcanic eruption launched enormous amounts of gases into the atmosphere, compromising global ocean chemistry, causing climate change and, possibly, the destruction of the ozone layer, which would explain the land extinction. In studying the climate change in the past or present, the coupling of the oceans with the atmosphere is crucial.

The extinction serves as a laboratory to what is going on now, as even larger amounts of CO2 are being launched into the atmosphere, causing the rapid acidification and warming of the oceans. In 1996, Andrew Knoll, a Harvard geologist, and collaborators suggested that increases in atmospheric CO2 had severe consequences for marine life in the late Permian Earth. "Today, humans turn out to be every bit as good as volcanoes at putting carbon dioxide into the atmosphere," he said to the NYT's Mitchell.

Of course, we are not at the late Permian, a time when all continents were united as one, Pangea, and the ocean's chemistry was different. But the lesson is loud and clear for those who choose to hear it: increased concentrations of atmospheric CO2 acidify the oceans and kill marine life. The key difference is that now we are the main culprits and can take measures to attenuate the ensuing changes.