This post is about “Extinctions and Optimism: What a recent study says and doesn’t say about extinctions,” by Jason Anthony. I’ll admit that I was concerned this Substack post of his would be another apology for cautious thinking about what we should do today.

But really, this is a delightful post. Anthony is looking at geological timeframes and presents, early in, a graph of “Big Five Mass Extinctions in Earth’s History,” which he got from Our World in Data. I love me a good graph and this one is a terrifically rich infographic that shows the five mass extinctions throughout geological history, but it also presents spikes of 16 lesser extinction events. Now there’s a phrase I’d never imagined writing: “lesser extinction events.”

By the way, I came across this post through Andy Revkin’s cross-posting on Sustain What. A tip of the cap, sir.

Later in the post Anthony reports that species extinctions have been declining for the last hundred years, contradicting the typical cry about vast biodiversity losses. He quotes Peter Brannen’s book, The Ends of the World. Here’s an interesting Brennen quote:

Though we’ve proven to be a destructive species, we have not produced anything even close to the levels of wanton destruction and carnage seen in previous planetary cataclysms.

Of course, considering that one such “planetary cataclysm“ was the super high speed collision of Earth with a really large asteroid, I’m not sure there’s much comfort to be taken in Brannen’s quote.

Anthony goes on to examine the geological record and argues that “the common wisdom about biodiversity in the Anthropocene is that it is in steep decline and that the losses are piling up.” He suggests that we’re possibly past “peak extinction,” but he also argues that past extinctions turn out not to be good predictors of future extinctions. If I understand this right, that’s because we’re talking about complex Earth systems of different sorts and characteristics. It turns out that one mass extinction is not like any other. Makes sense.

Anthony also writes: “A warming climate over the last two centuries was found, surprisingly, not to have increased extinctions. Not yet, anyway.”

“Not yet, anyway.” Sobering words.

While we can’t extrapolate from the earlier extinctions to understand the threats to biodiversity now, we do know that the disruption of the carbon cycle is a constant factor in mass extinctions. Global warming is disrupting the carbon cycle in our time, and that’s troubling. He writes:

Homo sapiens are a recent Pleistocene/Holocene blip in terms of our time on Earth, but in a geological nanosecond our population and culture have metasticized into something like a CO2-spewing supervolcano. Looked at another way, the impacts of our species have not arrived as quickly as those from the End-Cretaceous Manhattan-sized asteroid, but they’re certainly occurring faster than the millennia of volcanic purges that led to other mass extinctions. We’re neither asteroid nor supervolcano, of course, but we are consciously exhibiting symptoms of both.

And that, friends, is a clear statement about dangers from runaway carbon emissions, a.k.a., climate change. Apparently, those people who may feel offense in Anthony’s counter-intuitive report that biodiversity is doing okay at present really only have to wait a while longer to be proved right, unfortunately.

Anthony’s post is an interesting mixture of hope—we’re protecting biodiversity to the point where extinctions have been slowing—and distress—the oceans are turning acidic, major ocean systems like AMOC are slowing down, oxygen is being reduced under the waves. “The extinction rate is not what we thought it was, but the future remains unclear.” Indeed.

He ends with some grounds for aspiration, meditating on an old fossil he describes as his talisman; “…we live in relationship with deep time, and that even in our mayfly-like little lives, we get to decide what that relationship will be.”

Part of this relationship with today has to be the rejection of fossil fuel corporations as anything other than an enemy to our future and as a threat continuing to mess with the Earth’s carbon cycle in negative ways. Just because specie extinctions aren’t as bad as they could be today doesn’t mean we’re unlikely to avoid all sorts of ecological collapses if we don’t get greenhouse gas emissions moving toward net zero. But don’t look to me for that answer. Look at geological history.

And then get to work on the clean energy transition.

Here’s a nifty infographic Anthony includes in his recent Substack post. I love a good infographic.

The post Extinctions are Interesting in Relation to Climate Change first appeared on David Guenette.