I know I already published a link to this in yesterday’s Truthout digest, but this article-like the video the other day-is too important to miss. I hope you will read it and share it widely. Some people would rather feel smugly “right” while their own species and most life on Earth comes to a nasty end in widespread extinction but some of us would rather take the chance of learning something and acting to change the outcome.
I hope most of you are like me-more interested in the good final outcome than inflating your ego by mocking others in the moment.
(Image: Methane molecules via Shutterstock)
In the past, when I’ve written about climate and mass extinctions, I generally single out two of them — the one 65 million years ago that ended the dinosaur era, and the one about 250 million years ago that killed off almost everything then alive and made room for the dinosaurs to develop.
The dinosaur-killing extinction is called the “Cretaceous–Paleogene (K–Pg) extinction event” since it occurred between the Cretaceous Period and the Paleogene Period. The earlier extinction, also called the “Great Dying,” is the “Permian–Triassic (P–Tr) extinction event” and occurred between those two geological periods.
But starting from the first explosion of life on earth, some 540 million years ago, all geological periods are grouped into just three “eras” — the era of Old Life (Paleozoic Era), the era of Middle Life (Mesozoic Era, or the age of dinosaurs), and the era of New Life (Cenozoic Era, or the age of mammals and man).
The Paleozoic Era lasted over 290 million years. The Mesozoic Era lasted 185 million years. We’re in the Cenozoic Era now, and it’s lasted 65 million years.
Just three major divisions since life first exploded. And guess what divides these eras? The two mass extinctions I mentioned above. Here’s what that looks like in one handy chart:
So yes, mass extinctions — certainly mass extinctions of this size — matter. As I argued here and here, we may not using our little climate problem just to exit the Holocene (our current 12,000-year geological division). We may be exiting the entire Cenozoic Era. Now that’s a world-historical event.
The Great Dying Was Probably Caused by Atmospheric Methane
So the first part of today’s piece to keep in mind is the major geological divisions. And make no mistake, the Great Dying was a great dying, the mother of all great dyings (my emphasis everywhere):
It is the Earth’s most severe known extinction event, with up to 96% of allmarine species and 70% of terrestrial vertebrate species becoming extinct. It is the only known mass extinction of insects. Some 57% of all families and83% of all genera became extinct. Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after any other extinction event, possibly up to 10 million years. [Other sources say 30 million years.]
Now the second part of this discussion. People have been puzzled about the cause for a long time, and how it managed to be so … effective. Turns out that researchers at MIT may have found the answer — atmospheric methane. It’s the only explanation that fits the facts, and there’s much evidence to support it. Given the factual data that’s been assembled about the event, all of the other, previously-thought-plausible explanations have to be dismissed. Not one of the others could explain the combination of facts now known.