The damning evidence keeps rolling in with regards to volcanoes and mass extinctions. The latest is in the journal Geology regarding the mother of all extinction events — the end-Permian event 252 million years ago. The new evidence is from the Salt Range in Pakistan, where fossil plants reveal a huge input of carbon dioxide into the atmosphere that yanked the global climate into a new regime.
Sound familiar? Yeah, that’s the same thing we are worried about happening under the current global warming event. Back in the Permian it looks like it was the Siberian Traps volcanic eruption that released the carbon dioxide. Now it’s humans digging up and burning fossil fuels, releasing into the atmosphere millions of years worth of naturally sequestered carbon.
The Siberian Traps are a gigantic volcanic deposit unlike anything that has been laid down in the time that humans have inhabited Earth. And that’s a good thing (the timing, I mean), because it’s beginning to look like these sort of jumbo lava flows — which can ebb and flow for millions of years before they are finished — are the prime suspects in most of the worst mass extinction cases in our planet’s history (yes, even the one that killed the dinos).
In this particular study researchers from Norway, the Netherlands, Switzerland and Pakistan focused on carbon data locked up in land plant cuticles (essentially, the outermost layer of plant skin) and fossil wood fragments. They used the carbon-13 isotope in the plant cuticles as a proxy for atmospheric CO2 across the Permian-Triassic boundary — which is marked by the loss of 96 percent of all marine species, 70 percent of all land vertebrates, and is the only mass extinction known to have seriously perturbed insects (who otherwise tend to ride out hard times rather nicely). The Pakistan cuticle carbon reveals a shift in carbon isotopes that reflects a surge in atmospheric carbon dioxide.
Is this “proof” of the cause of the worst mass extinction? No. But it’s pretty damning evidence and hard to come up with any other possible cause of the die off that can be found in the geological record. Does it have any bearing on us today? Only the same lesson all history has to offer: If we don’t learn from it, we will be condemned to repeat it.
Image: The Salt Range in Pakistan is rich in fossil bearing rocks that cross the Permian-Triassic boundary at 252 million years ago. This boundary marks the Earth’s most extensive mass extinction event. Image credit: WikiCommons