“There are very strong indications that the current rate of species extinctions far exceeds anything in the fossil record.” That’s from a 2010 special issue on climate change and biodiversity from the UK’s Royal Society.
In 2011, a Nature Geoscience study found humans are spewing carbon into the atmosphere 10 times faster now than 56 million years ago, the Paleocene-Eocene Thermal Maximum (PETM), a time of 10°F warming and mass extinction.
An even more ancient extinction is the subject of a new study in Science (subs. req’d), with the tongue-twister title, “Zircon U-Pb Geochronology Links the End-Triassic Extinction with the Central Atlantic Magmatic Province.”
As the MIT News release puts it:
Some 200 million years ago, an increase in atmospheric CO2 caused acidification of the oceans and global warming that killed off 76 percent of marine and terrestrial species on Earth.
Whereas human activity is the source of the rapid surge in CO2 emissions today, the source of the surge 200 million years ago is now widely thought to be volcanoes:
… most scientists agree on a likely scenario: Over a relatively short period of time, massive volcanic eruptions from a large region known as the Central Atlantic Magmatic Province (CAMP) spewed forth huge amounts of lava and gas, including carbon dioxide, sulfur and methane. This sudden release of gases into the atmosphere may have created intense global warming and acidification of the oceans that ultimately killed off thousands of plant and animal species.
Now researchers at MIT, Columbia University and elsewhere have determined that these eruptions occurred precisely when the extinction began, providing strong evidence that volcanic activity did indeed trigger the end-Triassic extinction.
Today, of course, notwithstanding the claims of some disinformers, “Humans emit 100 times more CO2 than volcanoes,” as Skeptical Science explains in one of their classic myth-debunking posts.
So what is the connection between what happened in the End-Triassic Extinction and our current mass extinction? As ClimateWire (subs. req’d) explains: