It’s getting harder and harder to find something optimistic about. Seeing science knee-capped and obnoxious snots under Musk’s employ rifling through the IRS files and plotting to destroy Social Security (Hey! That’s my money! It’s not for billionaires to steal) is incredibly discouraging. I found something that looks on the bright side of climate change, though. The Miocene might be a good model for our future.
The Miocene, roughly 5-20 million years ago, had CO2 levels similar to where we’re going as we blast past recommended limit. It was generally warmer and wetter! That has some appeal as I sit here in a region at -30°C. It wasn’t a terrible world at all — primates were diverse and thriving, we had all these interesting mammals, “From Dryopithecus, a lineage of extinct primates that included forerunners of humans, to the toxodonts, large-hoofed mammals with long, curved incisors, to mammals similar to sloths, armadillos and anteaters, to marsupial carnivores”…it was great!
Significantly, the Miocene was a nearly 18 million year epoch full of change, albeit far slower change than ours. It started with a period of glaciation that must have been a chilly change from the greenhouse-like Oligocene, and ended with a prolonged period of glaciation, too. But through much of the Miocene, it was a warm world compared to today’s, a high CO2 planet that gradually cooled over millions of years until ice sheets developed in the Northern Hemisphere and Antarctica.
Around the middle of the epoch, we reached what is called the Miocene Climate Optimum (MCO), a roughly two million year-long greenhouse period when the world experienced its last period of sustained warmth, and the CO2 level was at least 500 ppm. This is the period we’re talking about, most specifically, when we talk about the Miocene as a proxy for our future, although changes throughout the Miocene are relevant: basically, from the middle Miocene Earth went through a process roughly opposite the one we are experiencing (and causing) today.
See? How can you dislike something called a “Climate Optimum”? It looks like paradise! Sign me up — these Minnesota prairies would be so exciting with little horses and hippos and Thylacosmilusand chalicotheres gamboling about in the lush vegetation.
The plants are going to love it.
Carbon dioxide levels affect plants by allowing for greater photosynthesis rates, and by increasing water use efficiency, in that plants can achieve the same amount of photosynthesis with less loss of water through the pores in their leaves, because higher availability of CO2 absorbed through open pores means they can keep them closed more of the time. Thanks to all this, it was also “a globally greener Miocene world,” as Reichgelt and West write in the 2025 paper. Various forms of evidence suggest that the biosphere was more productive during the Miocene compared to now, and that at higher latitudes, this effect was more pronounced.
Except for one major problem: evolution does not run backwards. No chalicotheres await us, especially since we’d be entering a neo-Miocene with a depauperate fauna.
Sadly, the taxodonts will not grace our future world. The long-armed, horsey Chalicotheriidae, reminiscent of Bojack Horseman, won’t be joining us at the bar. Smilodon, the catty predator whose ancestors emerged in the early Miocene, will not smile on us again. Nor the “bizarrely specialized” family of carnivorous marsupials, Malleodectidae, which used their massive ball peen-like third premolars to crush snails. Not the dog bears, Hemicyoninae, who emerged before and lived through the Miocene, nor the bear dogs, Amphicyonidae, which died out by the late Miocene. Evolution doesn’t work like that. Barring the odd de-extinction attempt, what’s lost is gone forever (that includes, thank goodness, the terror birds.)
Expect wild pigs and deer, already doing well, and novel species exploring new environments: I expect the descendants of raccoons and rats to thrive. Humans, not so much. We don’t do so well in the face of widespread environmental disruption, we like nice stable tame-able places where we can rely on crops to come in dependably. We’ll be starting with ecological wreckage and then amplifying the swings of climate and weather, which is a recipe for radical destabilization.
It’s also possible that we’re being seduced by the idea that the Miocene might represent a “happy medium.” As Steinthorsdottir and colleagues write, “More pessimistic scenarios of unmitigated greenhouse gas emissions quickly move us beyond the Pliocene state, pushing Earth’s systems into a potentially vulnerable position where many of its ‘tippable’ subsystems such as glaciers, sea ice, forest biomes, deserts and coral reefs will be permanently destabilized […] an ‘intermediate’ deep-time climate analog, where boundary conditions are close to modern but extreme climate changes occurred, is therefore of great interest.”
As humans we have a notorious tendency to believe that whatever’s in the middle of two given extremes is moderate, cozy, all around OK. (In politics, this results in the Overton Window.) But Miocene-style hydrological or water cycles favor high altitude wind events, like cyclones and hurricanes, that transport heat and moisture evaporating from the tropics to higher latitudes, or California’s intense seasonal rainstorms. The future may be lush, sure, but it’ll also be erratic and dangerous for us. And the “tippable” subsystems Steinthorsdottir mentions may have tipping points that occur well within a Miocene-like context, as scientists have warned.
Whenever a paleoclimatologist tells you a scenario is “of great interest”, it’s time to run.
Sorry. I told you it’s hard to find anything to be optimistic about.
Time to run?
Don’t run to Gaza province, Mozambique, East Africa. Trump and Musk say Hamas are active there. They have even learned to make explosives from condoms! (Is this some special East African condom brand? And can I order some?)
Can we please “uplift” the bonobos so they can take over if we go exinct? I don’t think they are much bothered by heat.
Smilodon may not re-evolve, but there’ve been several sabre-toothed cats, so I’d expect another one to evolve to hunt feral horses and giant rabbucks.
I was dreaming when I wrote this
Forgive me if it goes astray
But when I woke up this morning
Could have sworn it was judgment day
The sky was all greenhouse gaseous
People running everywhere
Trying to run from global warming
You know I didn’t even care
Say say, oops we’re out of time, going to start the Anthropocene
So tonight I’m gonna party like it’s the end of the Holocene
Yes. QFT.
Especially about doing anything about climate change.
Even a lot of hard core climatologists have now given up.
The original goal was to keep Global Heating to 2 degrees C.
We aren’t going to make it.
We just ran past 1.5 degrees C.
So how is the world doing at lowering CO2 emissions?
Not very good here.
The world will pump out 104.7 million barrels of oil per day.
This is a record for the amount of oil produced.
So OK, here it is 2025.
Global temperatures are going up and we are on the way from 1.5 C to 2.0 C.
CO2 levels are increasing rapidly with no slowdown in sight.
World oil production just set a record.
The USA just declared by an Executive Order than Global Warming doesn’t exist and pulled out of the Paris Climate Agreement.
That is one less thing to worry about.
We tried to stop Global Warming and failed.
We lost.
We are now in the era of Global Adaptation, to a high CO2, warmer world.
The lush Miocene also didn’t have 8.2 billion always hungry, always thirsty human beings mucking about and fighting each other.
John Watts @ 6
…And that is why I am joining the bioweapons division of the Umbrella Company.
birgerjohansson ‘@1
On the question of condoms and bombs I recommend the BBC’s latest More or Less programme if you weren’t aware of it. https://www.bbc.co.uk/programmes/w3ct5trh I find their programmes useful myself
John Watts, once climate change kicks in for real, there will no longer be 8.2 billion of us, but your broader point is well taken: It’s going to be quite a lifestyle adjustment for the ones who are left.
Why worry about climate change? We’ve got a couple of potential killer asteroids…that we know about…coming up in the next few years. They’re no match for the Chicxulub event, but depending on if/when/where they hit it could significantly disrupt human civilization. Of course, we might learn about one as big as Chicxulub any minute now…or maybe not. Given the current political situation, all research into these matters is likely to be killed because it’s a waste of money and billionaires don’t have any money to waste. So nothing will be done about any of these risk except sweep it under the rug, stop funding any research, and smirkingly tell das Volk…um folks…there’s nothing to worry about. Here have some Ivermectin. Bleach all around. Got to church and pray for your sins. Bend your head over until you can kiss your ass good bye. Well there ain’t no time to wonder why, whoopee we’re all going to die.
The right will always have a much easier time convincing the knuckle-dragging masses because people are lazy and building a better society takes work, materially and culturally. Maintaining the status quo or pining for some long-lost Golden Age that never really way is sooooo much easier and doesn’t challenge our pre-conceived notions of the world.
@ 7
I’ve got competing offers from Weyland-Yutani and Arasaka, myself.
Just for fun, I ran a simple calculation for how much it would cost to reduce CO2 emissions by Direct Air Capture, the last line technology we are now working on.
Human activities release around 40 billion tons of CO2 per year.
Direct Air Capture is projected to cost $300 per billion tons removed at scale.
Which comes out to $12 trillion dollars to remove all that CO2 per year.
World GDP is $104 trillion.
So we would have to spend 12% of world GDP per year to do that.
This is barely possible if everyone makes huge sacrifices.
The world is already full of billions of poor people, many of which aren’t too far above the income needed for survival.
I don’t see this happening unless we are looking at a human extinction event and a few billion people have already died.
Raven, No. 12, I don’t even see it happening if there is a human extinction event and a few billion people have already died. At that point the worst of the damage would already have happened and the ones that are left would say it’s everyone for themselves.
Actually, that cooling started quite early in the Oligocene judging from the pollen profile. In the warmest part of the Miocene, I frequently found walnut pollen in Arctic Canada and Alaska.
There is work being done on exotic molecular cages to capture CO2 directly at the sources.
There is also work being done by countries like Norway on sequestring the CO2 by injecting it in porous rock.
I have no estimates for cost.
I gather that the main problem for ecosystems during this episode is the sheer rate of change.
None of this having hundreds of thousands of years or more for them to adapt and evolve, as they did back in the day.
(So, not really comparable)
the only good thing if it is good at all is those of us who survive to see it undeniably happen will be able to say in the midst of the change “we told you so” which wont really help but seems pretty clear that there is little help to be had in our ultimate survival any way
quick googling, miocene climatic optimum was 18.4 C, vs 15 C in 2024. the “paleocene-eocene thermal maximum” which was a low-key extinction event was 23 C. given the lead foot on the accelerator of warming, given the way cycles make everything worse, given how much misinfo there is even from sources you’d think you could trust, because of the money, because big business is literally assassinating people right now, i feel like banking on the worst case scenario.
trump’s push for greenland makes perfect sense in the light of him fully expecting florida to disappear. he’s looking to recreate florida at a more northerly altitude. maybe somebody suckered him into believing the MCO prediction vs. the PETM prediction, because i wouldn’t even count on that scheme being feasible.
MFs are reverse terraforming.
from the dubious AI summary about the PETM:
“During the Paleocene-Eocene Thermal Maximum (PETM), the most significant extinction event was observed among deep-sea benthic foraminifera, with estimates suggesting around 35-50% of species within this group going extinct; however, overall, the PETM is not considered a mass extinction event as the extinction rates across most other life forms were not significantly elevated compared to background extinction levels.”
that blows, but it’s better than i was genuinely hoping for.
poorly phrased last sentence. i think you know what i mean. my whole shit is busted lately.
and very much agree with john morales on the rate of change. life won’t have time to adjust, vs. the PETM, and we are already causing an extinction event: “current extinction rate is often estimated to be thousands of times greater than the background extinction rate” … i think this will be survivable for some amount of humans, because we have amazing mental capabilities and versatility in diet. but everything outside the polar circles may be hotter than humans can live through for big swathes of the year.
i hope to live to see what remains of the profiteers of big oil drawn and quartered by a furious world.