The collapse

A couple of weeks ago, I wrote about the spike in atmospheric oxygen concentration -- by some estimates, rising to 35% -- during the Carboniferous Period, triggered by explosive growth of forests, and allowing arthropods like insects, arachnids, and millipedes to grow to enormous sixes.

The good times, though (for them at least), were not to last.  Around three hundred million years ago, there was a sudden drop in oxygen and rise in carbon dioxide.  This triggered rapid climatic shifts that resulted in the Late Carboniferous Rain Forest Collapse, which saw a major alteration from the swamp-dwelling plants and animals at the height of the period to species that could tolerate the dry heat that was to persist throughout the next period, the Permian.  (This set up the rise of reptiles, which would see their peak in the dinosaurs of the Mesozoic.)

Artist's depiction of the mid-Carboniferous swamps (ca. 1887) [Image is in the Public Domain]

The source of the excess carbon dioxide was very likely volcanic.  Besides the fact that lava can contain dissolved gases (mostly carbon and sulfur dioxide), the heat of the eruptions may have caused the oxidation of the plentiful limestone and coal deposits formed during the earlier lush, wet part of the period -- a precursor of the much bigger disaster that was in store fifty million years later, when at the end of the Permian, the Siberian Traps erupted and tore through a huge amount of the sequestered carbon, causing widespread global anoxia and climate change, and the largest mass extinction ever.

By some estimates, ninety percent of life on Earth died.

But the rain forest collapse at the end of the Carboniferous was bad enough.  A study that came out this week in Proceedings of the National Academy of Sciences found the anoxia/hypoxia hit the oceans the hardest, where the oxygen levels rapidly dropped by between four and twelve percent, with a commensurate rise in dissolved carbon dioxide.  When carbon dioxide dissolves in water, it produces a weak acid -- carbonic acid -- lowering the pH.  Organisms that make their shells out of calcium carbonate, like mollusks, brachiopods, and corals, literally dissolved.

You ready for the kicker?

The study's estimate of the rate of carbon dioxide release during the Late Carboniferous Rain Forest Collapse is a hundred times smaller than the rate we're putting carbon dioxide into the atmosphere today through burning fossil fuels.

"This is a huge discovery, because how do you take an ocean sitting under an atmosphere with much more oxygen than today and permit this?" said Isabel Montañez of the University of California - Davis, senior author of the study.  "The message for us is, 'Don't be so sure that we can't do this again with our current human-driven release of carbon dioxide.'"

The problem is, the current administration is in the pockets of the fossil fuel industry, and is doing their level best to pretend this isn't happening, and to discredit anyone who says it is.  Worse, actually; they've cancelled funding for any scientific research about climate.

Because apparently "la la la la la la not listening" is now considered wise political policy.  This, despite warning signals like the eastern half of the United States sweltering this past week under the most extreme heat wave we've had in over fifty years.

So I'm expecting studies like the one released this week by Montañez et al. to receive exactly zero attention from the people who actually could work toward addressing this situation.  It brings to mind a quote from Upton Sinclair, uttered almost a century ago: "It is difficult to get a man to understand something when his salary depends on his not understanding it."

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Time to act

I know we really don't need anything else to worry about.  World events have been depressing enough, and here in the United States we've got an election on Tuesday that is making me pop Xanax as if they were Skittles.  But I ran across something in a book I'm reading that was absolutely jaw-dropping, and not in a good way, and I knew I would be seriously remiss in not writing about it here.

I mentioned a few days ago (in a post about some bizarre volcanoes in the East African Rift Zone) that I've been reading Tamsin Mather's wonderful book Adventures in Volcanoland: What Volcanoes Tell Us About the World and Ourselves.  Mather's specialty is monitoring gas production from volcanoes, and using the composition of offgassed material to gather information about magma characteristics and the likelihood of eruptions.  She's traveled all over the world collecting and analyzing samples, comparing hotspot volcanoes (like the ones in Hawaii) to rift volcanoes (like Ol Doinyo Lengai in Tanzania) to trench/subduction volcanoes (like Etna, Vesuvius, Krakatoa, Fujiyama, the Andes, and the North American Cascades).  Her research puts her in position as one of the world's foremost and most knowledgeable experts on volcanic offgassing, and what it means for our understanding of what is going on inside the Earth's mantle.

In her book, she not only references currently-active volcanoes, but prehistoric eruptions -- and one of those she discusses is the astonishingly huge Siberian Traps.  

[Image licensed under the Creative Commons OlgaChuma Ольга Чумаченко, Плато Путорана-3, CC BY-SA 3.0]

This eruption, of a type known as a large igneous province or flood basalt, happened 252 million years ago, at the end of the Permian Period.  Flood basalt eruptions occur when something rifts the crust of the Earth and deep-source, extremely hot basaltic (low silica content) lava flows out.  This lava is incredibly fluid, and fills up valleys like water fills a bowl.  In the case of Siberia, it was a quantity that beggars belief; current estimates stand at around four million cubic kilometers of lava.  The disaster this caused was amplified by the fact that prior to the eruption, the Earth had had a long period of warm, wet climates pretty much worldwide, facilitating the growth of widespread swamps and rainforests.  The age when this occurred is called the Carboniferous Period, so named because all that dead compressed plant matter locked up gigantic quantities of atmospheric carbon, forming enormous seams of coal.

When the Siberian Traps erupted, the lava ripped its way through those massive coal deposits, and the carbon they contained was suddenly returned to the atmosphere as carbon dioxide.  Mather writes:

Estimates of total carbon dioxide emissions over the million-year-scale lifetimes of these basaltic floods are in the region of tens to hundreds of trillion tonnes...  Estimates of varying emission rates over the very long lifetimes of these provinces are harder to make than the totals, but one recent study put the maximum emission rate during the Siberian Traps at around eighteen billion tonnes per year.

The result was widespread disruption of the climate, global marine anoxia, and the largest mass extinction ever -- the Permian-Triassic Extinction, which wiped out on the order of ninety percent of life on Earth.

The kicker comes in the very next paragraph, when Mather tells us that the rate of carbon dioxide production from the most massively devastating volcanic eruption on record, the rock from which covers an area of seven million square kilometers, is half the rate our current fossil fuel use is currently churning out carbon dioxide.

I don't exaggerate when I say I had to read that passage three times before I was convinced I'd understood her correctly.

I've all too frequently heard laypeople give a sneering chuckle at the climatologists, saying stuff like, "What a lot of bullshit.  One volcanic eruption emits more carbon dioxide than all the cars on Earth do."  They rarely cite a source, and when they do it's from something like the fossil-fuel-industry-funded Heartland Institute, but -- because this opinion is a great excuse for continuing to do stuff the same way we always have -- they almost never get challenged on it.

It's astonishing how easy it is to accept a false viewpoint when it gives you a comforting reason not to do anything inconvenient to your lifestyle.

But here's the straight scoop from Tamsin Mather, who (allow me to reiterate) is a volcanologist who specializes in analysis of volcanic offgassing:

Despite the wide error bars in our estimates of the global rate of volcanic carbon degassing, what we can know is that these natural emissions pale into insignificance compared to what humans produce.  In 2019, human fossil-fuel burning released over 35 billion tonnes of carbon dioxide into our atmosphere.  This is seventy times more than even our most generous current estimates of global magmatic carbon degassing.  In 2022, the aviation industry alone emitted 800 million tonnes of carbon dioxide, eclipsing estimates of that from our planet's background tectonism before even considering other sectors of human industry.  We cannot look to Earth's volcanism today to reassure ourselves that our rate of carbon emission might not be too much of a change in terms of our planet's natural cycles.  Powerful as the forces of tectonics that daily drive the slow creep of plate movement and volcanic activity across the globe are, the human race has currently surpassed them in terms of its carbon dioxide flux to the atmosphere.  It is apposite to reflect upon the level of responsibility that should appropriately come with the level of power attained by our species that, by this carbon metric, overwhelms all Earth's volcanoes.

Despite this, we have a candidate for president here in the United States -- I doubt I need to tell you which one -- who has stated he wants to discontinue investment in renewable energy and withdraw from the Paris Accords, and frequently says "Drill baby drill, and frack frack frack!" to cheering crowds.

Anyhow, I'm sorry to post alarming stuff, but perhaps now isn't such a bad time after all.  We have the chance to make a difference not only by our actions and choices, but in the voting booth.  It put me in mind of a conversation that occurs in my novel In the Midst of Lions, which seems a fitting way to end this post:

Mary Hansard's face registered near panic.  "It's not just here.  It’s everything we know.  Soon it’ll all be gone, and if we don’t find a way out, us with it.  We've got to do something, now.”

Soren glanced at Dr. Quaice.  “Okay, this is scaring the shit out of me.”

Mary tightened her grip on Soren’s sleeve.  “Good.  Good.  You should be scared.  Scared people act.” She hitched a sob.  “Complacent people die.”

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A Jurassic wake-up call

About 183 million years ago -- during the Toarcian Age, one of the subdivisions of the early Jurassic Period -- there was a sudden and puzzling extinction.

Things had been recovering nicely after the End-Triassic Mass Extinction, eighteen million years earlier.  While dinosaurs were not yet at the peak they would hit in the later Jurassic, they were well on their way to taking over the place.  The temperatures were cool -- there's evidence of widespread glaciation during the ten million years prior -- but by and large, everything seemed to be coping just fine.

Then, suddenly, wipeout.

It wasn't as big as some of the truly dramatic mass extinctions the Earth has experienced, but that doesn't mean it was insignificant.  Marine invertebrates got clobbered, dropping both in diversity and in overall numbers.  Over ninety percent of coral species went extinct.  Two entire orders of brachiopods died; bivalves, ostracods, and ammonoids survived, but with greatly reduced populations.  Coelophysid and dilophosaurid dinosaurs got wiped out completely.  Seed ferns and lycophytes declined sharply, to be replaced by cycads and conifers.

Fossil seed fern [Image is in the Public Domain]

All of it occurred rapidly -- the current estimates are less than five hundred thousand years, which is a snap of the fingers geologically.

So what happened?

The culprit seems to have been the Karoo-Ferrar Large Igneous Province, an enormous volcanic formation (estimated at about three million square kilometers) now underlying much of southern Africa, eastern Antarctica, and southwestern South America.  At this point, Gondwana -- the southern half of the supercontinent of Pangaea -- had just begun to break up, and this massive series of eruptions was part of the process of rifting.  But what caused the extinction was not the eruption itself -- it was the sudden spike of atmospheric carbon dioxide, which swung the climate from a glacial period to a hothouse.  A study released last week by a team at Duke University found evidence of a twenty thousand gigaton carbon dioxide pulse, triggering not only a drastic temperature increase, but widespread ocean acidification and anoxia.

According to the study, during the event, eight percent of the global seafloor -- an area three times that of the United States -- became completely anoxic.  The pH dropped so much that animals with calcium carbonate exoskeletons literally dissolved.  Rainfall patterns shifted dramatically, impacting terrestrial biomes as well.  By the time things began to recover, it was a changed world, all in a matter of a half of a million years.

Ready for the punchline? 

Today's rate of carbon dioxide increase in the atmosphere is over two hundred times what it was during the Toarcian Extinction Event.

Twenty thousand gigatons in five hundred thousand years is a lot, and had a devastating effect on the world's ecosystems; we've put two thousand gigatons into the atmosphere in the past two hundred years.  

Is it any surprise why the scientists have been trying like hell to get everyone's attention?

"We just don't have anything this severe [in the geological record]," said paleoclimatologist Michael Kipp, who co-authored the study.  "We go to the most rapid CO2-emitting events we can in history, and they're still not rapid enough to be a perfect comparison to what we're going through today. We're perturbing the system faster than ever before.  We have at least quantified the marine oxygen loss during this event, which will help constrain our predictions of what will happen in the future."

None of this is meant to stun people into giving up.  We have got to get a handle on this.  Yes, we've crossed several benchmarks the climate scientists have warned us about.  But every tenth of a degree's further increase we can prevent will mitigate the effects of what we're doing.  We have got to stop electing politicians who shrug their shoulders about anthropogenic climate change, most strikingly Florida's belligerent and willfully stupid Governor Ron DeSantis, who recently signed a law striking any mention of climate change in state statutes, banning offshore wind turbines, and deregulating natural gas production, transport, and use.  

In one of the lowest-lying, most hurricane-prone states in the country.

Maybe it will take our getting slapped hard to wake us up; we don't have a good record of addressing problems that aren't right in front of our faces.  Events like the massive heat dome that just cooked the southern, central, and northeastern states are just the beginning, and are easily forgotten once they pass.  They're predicting a vicious hurricane season, fueled by a central Atlantic with a surface the temperature of bath water, but we've seen dire predictions before and gone on our way as if nothing was amiss.

So how many lives will it cost before that wake-up call is finally listened to?

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The fingerprint of life

Springboarding off yesterday's post, which suggested that -- from a biochemical standpoint, at least -- extraterrestrial life might be way more common than we'd thought, today we look at how we might find out where it lives.

This is a thornier problem than it might seem at first.  Despite hopeful movies like Contact, picking up an alien radio signal makes looking for a needle in a haystack seem like child's play.  Consider the difficulties; you have to have your radio telescope pointed at exactly the right place in the sky, at exactly the right time, and tuned to exactly the right frequency, to pick it up as it sweeps by the Earth at the speed of light.  Even if you posit an extremely simple message, which repeats indefinitely (like Ellie Arroway's string of prime number blips), there's the problem that any kind of electromagnetic signaling follows the inverse-square law, meaning if you double the distance between the sender and the receiver, the intensity of the received signal goes down by a factor of four.  Triple it, and it goes down by a factor of nine, and so forth.

And the fact is, the distances we're talking about here are...

... astronomical.  (*rimshot*)

So the possibility of detecting some sort of radio signal (whether or not deliberately sent to attract our attention) is not zero, but pretty damn small.  And the other downside is that if that's all we're looking for, we're going to miss a huge slice of the living creatures that could be out there -- we'd only see the ones that have a technological civilization that uses radio waves to communicate.  From that approach, Earth itself would have appeared to be barren and lifeless until the use of radio became widespread, back in the 1930s.

Is there another way?

An alternate approach -- one that avoids at least some of these pitfalls -- is to look for biosignatures, chemical traces that might indicate the presence of life on a planet even if it hasn't reached the point of being technological.  The studies done on Mars that attempted to find Martian microbes took this approach; take a sample of soil, add some likely nutrients, and look for a sign of metabolism.  But this, too, has its inherent difficulties.  How do you tell the difference between Martian microbes chowing down on the food you gave them, and some exotic but abiotic chemical reaction?

A team of astronomers and biologists from the University of Birmingham and MIT have come up with a possible answer.  According to a paper in Nature Astronomy last week, there is a pair of dead giveaways; an atmosphere depleted in carbon dioxide but enriched in ozone.

Carbon dioxide is a highly stable compound, and on lifeless, dry planets like Venus and Mars, it makes up a significant percentage of the atmosphere.  (96.5% on Venus, 95.3% on Mars.)  The fact that despite the amount of carbon on the Earth, the quantity in the air is only 0.04%, is due mostly to the fact that the water in the oceans acts as a huge carbon sink, first dissolving the carbon dioxide, then reacting it with dissolved metal ions like calcium and magnesium to form minerals like the calcite and magnesite in limestone.  Without the oceans, all of that carbon would stay in the atmosphere -- and we'd be a lot more like the inferno that is Venus than the temperate world where we reside.

As far as ozone, the real tipoff for the presence of life would be gaseous oxygen, which is a highly reactive substance that, in the absence of something producing it pretty much continuously, would all be bound up chemically.  Ozone -- a chemical relative of oxygen, O3 instead of O2 -- is expected to be present in small amounts in any atmosphere with free oxygen, but is the astronomers' choice because its spectral signature is much easier to detect than oxygen's.

Likewise, carbon dioxide's spectral fingerprint is obvious because of its strong absorption in the infrared (a property that is directly related to the greenhouse effect and carbon dioxide's warming effect on atmospheres).

So it should be possible to analyze the light reflected from the surface of exoplanets that seem to be in the right temperature range, and look for two things -- low carbon dioxide (indicating liquid water on the surface) and high ozone (indicating something, possibly life, keeping molecular oxygen in the atmosphere).  See both of those things, the team said, and you're very likely looking at a planet that is inhabited.

Like I said yesterday, of course, "inhabited" doesn't mean "inhabited by bipedal humanoids with spaceships and laser guns."  But even so, the technique is intriguing in its simplicity.  The team suggested starting with relatively nearby planetary systems like TRAPPIST-1, which has seven known exoplanets and is only a little over forty light years away from Earth.

TRAPPIST-1 and its lineup of seven planets [Image is in the Public Domain courtesy of NASA/JPL]

So this is all tremendously exciting -- that astronomers are now taking the possibility of extraterrestrial life seriously enough to start proposing methods for searching for it other than just scanning the skies and hoping for the best.  After all, to go back to the movie Contact -- "if we're all alone in the universe, it seems like an awful waste of space."

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When the volcano blows

It's a point I've made here more than once; if you're trying to convince someone of something, your argument is not made stronger by lying about it.

The reason this comes up today is the horrible situation in Iceland, where (at the time of this writing) the people of the little village of Grindavík on the south coast of the Reykjanes Peninsula, due south of the capital city of Reykjavík, have been evacuated and are waiting for a volcanic eruption that stands a good chance of destroying the town completely.  The buildings and roads in the town have already sustained heavy damage from nearly continuous earthquakes, and the latest estimate is that there are places where the magma is only five hundred meters below the surface.  An eruption is nearly certain -- how extensive it will be is unknown.  (The village is only a few kilometers away from Fagradallsfjall, the volcano I got to see erupting when I visited Iceland in 2022.)

A photograph I took in August 2022

This is certainly awful.  But the whole situation is made worse because every time there's a volcanic eruption, it brings the climate change deniers howling from the dark corners where they hide, claiming that (as one of them put it) "the Climate Scammers conveniently ignore that a single volcanic eruption puts hundreds of times more carbon dioxide into the atmosphere than cars do.  Climate ups and downs happen all the time, and natural processes account for nearly all of it.  Wake up!"

Which would be a good argument if anything about it was true.

The "hundreds of times more" statistic is about the right factor -- but the inequality points the other direction.  Here's the actual situation, as per the National Oceanic and Atmospheric Administration:

You might not spot the volcanic carbon dioxide output on this graph right away, because it's the light blue line hugging the x-axis.  In fact, as Mark Gongloff points out, writing for Bloomberg, the 1980 eruption of Mount Saint Helens spewed ten million tons of carbon dioxide into the atmosphere, which seems like a lot until you find out that our burning of fossil fuels does that every two and a half hours.  Geologists estimate that even a cataclysmic eruption like the Yellowstone Supervolcano emitted on the order of thirty gigatons of carbon dioxide -- about what our fossil fuel use accomplishes every single year.

So not only are the climate change deniers coldly and callously capitalizing on the horrible situation unfolding in Iceland, they're doing so by crafting outrageous lies about it.

The fact that this claim is wildly wrong has not stopped it from being circulated all over the place by people who would very much like it if we didn't have to face head-on what we're currently doing to the planet we live on.  I get it; it's a hard conversation to have.  I have an electric car and solar panels and solar hot water, but even so, I very much live an affluent First-World lifestyle, with all that comes along with it.  I'm better situated than most if it came to a serious cutback in fossil fuel use, and it still would force me and my family into some difficult changes.

But we can't keep going as we are.  If this past year's insane weather didn't convince you of that fact, you're being willfully blind.

And the whole thing is not helped by circulating wildly wrong information whose sole intent is to lull everyone into further inaction.  I have no doubt that at least some of the people who are posting this stuff don't know it's wrong, and are guilty of the rather common sin of neglecting to fact-check.  But the ones who write these posts and create these memes -- they know it's a lie, and they do it anyway.

Which is somewhere beyond reprehensible.

So please, please, please... if you see someone posting this claim, tell them they're wrong.  Link this blog post if you like, or (better still) send them to the NOAA and USGS sites that lay the data out in unarguable form.  Because this is a falsehood with serious repercussions -- like endangering the long-term habitability of our own home world.

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Creepy crawlies

Whenever we have a wet summer -- not an uncommon occurrence in our rainy climate -- we have a plague of little pests trying to get into our house.

They're called millipedes, slinky guys maybe a couple of centimeters long, with lots of legs (not a thousand, though).  They're completely harmless; they don't bite like their cousins the centipedes do, and if you poke at them, they coil up into a ball.  So I guess they're really more of a nuisance than an actual problem.  They don't even damage anything, the way mice can.  Mostly what they seem to do is get in through every crack and crevice (there are lots of these in a big old house like ours), look around for a while, then curl up and die.

[Image licensed under the Creative Commons Totodu74, Anadenobolus monilicornis 03, CC BY-SA 3.0]

So I don't like them, and I wish they stayed outside, but in the grand scheme of things they're no big deal.  Imagine, though, if they were bigger.

A lot bigger.

Just last week, paleontologists announced the discovery on a beach in Northumberland, England, of a millipede fossil from the Carboniferous Period.  It's been dated to the middle of the period, about 326 million years ago.  It looks a bit like the millipedes I see trundling across my basement floor in summer.

Only this one was 2.6 meters long (approximately the length of a Mini Cooper), a half a meter across, and weighed something on the order of fifty kilograms.

It's been named Arthropleura, and holds the record as the largest-known arthropod in Earth's history.  Nothing is known for sure about its behavior; if it's like the rest of millipedes, it was a scavenger on leaf detritus, but there's no way to know for certain.  Given its size, it could well have been a lot more dangerous than the ones we have around now.  To paraphrase the old joke about five-hundred-pound gorillas:

Q:  What does a fifty-kilogram millipede eat?

A:  Anything it wants.

Those of you who are (like me) biology nerds may be frowning in puzzlement at this point.  How on earth could an arthropod get so big?  Their size is limited by the inefficiency of their respiratory system (not to mention the weight of their exoskeletons).  Most arthropods (millipedes included) breathe through pairs of holes called spiracles along the sides of the body.  These holes open into a network of channels called tracheae, which bring oxygen directly to the tissues.  Contrast that with our system; we have a central oxygen-collecting device (lungs), and the hemoglobin in our blood acts as a carrier to bring that oxygen to the tissues.  It's a lot more efficient, which is why the largest mammals are a great deal bigger than the largest arthropods.  (So, no worries that the bad sci-fi movies from the 50s and 60s, with giant cockroaches attacking Detroit, could actually happen.  A ten-meter-long cockroach not only wouldn't be able to oxygenate its own tissues fast enough to survive, it couldn't support its own weight.  It wouldn't eat Detroit, it would just lie there and quietly suffocate.)

So how could there be such ridiculously enormous millipedes?

The answer is as fascinating as the beast itself is.  As the temperature warmed and rainfall increased after the previous period (the Devonian), it facilitated the growth of huge swaths of rain forest across the globe.  In fact, it's the plant material from these rain forests that produced the coal seams that give the Carboniferous its name.  But the photosynthesis of all these plants drove the oxygen levels up -- by some estimates, to around 35% (contrast that to the atmosphere's current 21% oxygen).  This higher oxygen level facilitated the growth of animals who are limited by their ability to uptake it -- i.e., arthropods.  (At the same time, there was a dragonfly species called Meganeura with a seventy-centimeter wingspan.  And unlike millipedes, these things were carnivores, just as modern dragonflies are.)

Eventually, though, the system was unsustainable, and a lot of the rain forests began to die off in the Late Carboniferous, leading to a drier, cooler climate.  However, remember the coal seams -- by that time a huge percentage of the carbon dioxide that had fed the photosynthesis of those rain forests was now locked underground.  The fuse was lit for a catastrophe.

Fast forward to the end of the next period, the Permian, 255 million years ago.  What seems to have happened is a series of colossal volcanic eruptions that created the Siberian Traps, a basalt deposit covering most of what is now Siberia.  The lava ripped through the coal seams, blasting all that stored carbon into the atmosphere as carbon dioxide.  The temperature in the late Permian had been cool and dry, and the spike of carbon dioxide created a commensurate spike in the temperature -- as well as a huge drop in oxygen, used up by the burning coal.  The oxygen concentration seems to have bottomed out at around twelve percent, just over half of what it is now.  The extra carbon dioxide dissolved into ocean water, dropping the pH, and the increasing acidity dissolved away the shells of animals who build them out of calcium carbonate -- e.g. corals and mollusks.

Wide swaths of ocean became anoxic, acidic dead zones.  The anaerobic organisms began to eat through all the dead organic matter, churning out more carbon dioxide and another nasty waste product, sulfur dioxide (which gives the horrible smell to rotten eggs, and is also an acidifier).  The result: an extinction that wiped out an estimated ninety percent of life on Earth.  In short order, a thriving planet had been turned into a hot, dead, foul-smelling wasteland, and it would take millions of years to recover even a fraction of the previous biodiversity.

Of course, at highest risk would be the big guys like our friends Arthropleura and Meganeura, and the Earth hasn't seen giant arthropods like this since then.  Today, the largest arthropod known is the Japanese spider crab (Macrocheira), topping out at around twenty kilograms -- but crabs and other crustaceans have gills and an oxygen carrier called hemocyanin, so they can boost the efficiency of their respiratory system somewhat over their terrestrial cousins.  The largest insect today is the African Goliath beetle (Goliathus), at about a tenth of a kilogram.  And in today's atmosphere, it's at a pretty significant disadvantage.  They may look big and scary, but in reality, they're slow-moving, harmless creatures.  Kind of a beer can with six legs, is how I think of them.

So that's today's look at creepy-crawlies of the past.  In my opinion it's just as well the big ones became extinct.  The last thing I need is having to shoo a fifty-kilogram millipede out of my basement.

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Neil deGrasse Tyson has become deservedly famous for his efforts to bring the latest findings of astronomers and astrophysicists to laypeople.  Not only has he given hundreds of public talks on everything from the Big Bang to UFOs, a couple of years ago he launched (and hosted) an updated reboot of Carl Sagan's wildly successful 1980 series Cosmos.

He has also communicated his vision through his writing, and this week's Skeptophilia book-of-the-week is his 2019 Letters From an Astrophysicist.  A public figure like Tyson gets inundated with correspondence, and Tyson's drive to teach and inspire has impelled him to answer many of them personally (however arduous it may seem to those of us who struggle to keep up with a dozen emails!).  In Letters, he has selected 101 of his most intriguing pieces of correspondence, along with his answers to each -- in the process creating a book that is a testimony to his intelligence, his sense of humor, his passion as a scientist, and his commitment to inquiry.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Dark clouds

I still remember when I was about twenty years old, and I first heard about Carl Sagan's proposal to terraform Venus.

On first glance, this is a crazy idea.  Venus brings new meaning to the word "inhospitable."  Its average surface temperature is 462 C.  The atmosphere is mostly carbon dioxide, which is denser than Earth's air, so the pressures at the surface are immense.  (It's the density and composition of the atmosphere that's why early photographs taken by probes on Venus's surface looked warped, as if the probe were sitting at the base of a bowl; the refraction of what light makes it to the surface caused optical distortion.)  If being inside a pressure cooker isn't bad enough, its dense clouds are largely composed of sulfuric acid.

As Sagan himself said, "Venus is very much like hell."

But Sagan was an amazingly creative thinker, and he came up with a proposal for reworking the atmosphere and, possibly, making it livable for Earthlings.  He suggested detonating a rocket carrying a cargo of cyanobacteria in its upper atmosphere, dispersing them into the clouds.  Cyanobacteria are primitive photosynthetic single-celled life forms, and Sagan's idea was that the updrafts would keep at least some of them aloft.  As they tumbled about in the (relatively) temperate clouds, they'd photosynthesize, consuming some of the atmosphere's carbon dioxide and releasing oxygen gas as a waste product.

The idea is that the aerial microbes would multiply, and although some would inevitably sink low enough to fry, enough would stay up in the clouds to steadily drop the carbon dioxide content of the atmosphere.  Less carbon dioxide, less greenhouse effect; less greenhouse effect, lower temperature.  Once the cloud temperature dropped below 100 C, water vapor would condense, and it would rain out the sulfuric acid.

Far-fetched, perhaps, especially for its time.  But it was an exciting enough proposal that I recall discussing it eagerly with my college friends and fellow science nerds.

This all comes up because of a peculiar observation of Venus made recently, by teams at the Center for Astronomy and Astrophysics at the Technical University of Berlin, the University of Wisconsin-Madison, and the Japan Aerospace Exploration Agency.  What they've seen is that there are clouds of "unknown absorbers" darkening the upper atmosphere of the planet in patches -- enough to affect the weather.

A composite image of theVenus, using data from the Japanese probe Akatsuki.  [Image courtesy of the Institute of Space and Astronautical Science/Japan Aerospace Exploration Agency]

And there are astronomers who think these "unknown absorbers" are not the products of exotic Venusian chemical reactions -- but are airborne single-celled life forms.

"It is hard to conceive of what would cause a change in the [planet's] albedo without a change in the absorbers," said Sanjay Limaye, planetary scientist at the University of Wisconsin-Madison and co-author of a paper last week in The Astronomical Journal that seriously considered the possibility of the absorbers being life forms.  "Since there are few species which have physical, chemical and spectral properties that are consistent with the composition of the Venus clouds, they may have evolved independently on Venus."

The researchers are up front that extraterrestrial microbes are just one possible explanation of the peculiar darkening of the skies, which occurs with an odd periodicity along with an overall decrease in albedo since measurements started in 2006.  It may turn out to be simply a chemical reaction -- still the most likely explanation for the gas output from search-for-life experiments by the Mars landers -- but the fact that scientists are even considering the microbe hypothesis is encouraging and exciting.

Whichever it turns out to be, it seems fitting to end with another quote by Sagan: "Somewhere, something incredible is waiting to be known."

*****************************************

This week's Skeptophilia book recommendation is a classic: James Loewen's Lies My Teacher Told Me.  Loewen's work is an indictment not specifically of the educational system, but of our culture's determination to sanitize our own history and present our historical figures as if they were pristine pillars of virtue.

The reality is -- as reality always is -- more complex and more interesting.  The leaders of the past were human, and ran the gamut of praiseworthiness.  Some had their sordid sides.  Some were a strange mix of admirable and reprehensible.  But what is certain is that we're not doing our children, nor ourselves, any favors by rewriting history to make America and Americans look faultless.  We owe our citizens the duty of being honest, even about the parts of history that we'd rather not admit to.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Propping up climate denialism

Sometimes it appears that people only want to learn enough science to (1) sound scientific, and (2) prop up whatever ideas they already believed.

A sterling example came up a couple of days ago, thanks to one Ross MacLeod, who over at the sorely-misnamed Principia Scientific International explains to us why the Stefan-Boltzmann equation proves that there's no such thing as anthropogenic climate change.

The Stefan-Boltzmann equation, named after physicists Josef Stefan and Ludwig Boltzmann, basically says that the power radiated by an object is proportional to the product of its surface area and the fourth power of its temperature in degrees Kelvin.  It's not a hard relationship to comprehend, although it has deep and far-reaching (and difficult) implications for thermodynamics.  In any case, you can see why this equation is of interest to climate scientists, being that the Earth is both absorbing and radiating heat, and the relative rates at which these two happen are responsible for its average temperature.

So anyway, MacLeod quotes a NASA publication on climate, which says the following:

When it comes to climate and climate change, the Earth’s radiation budget is what makes it all happen.  Swathed in its protective blanket of atmospheric gases against the boiling Sun and frigid space, the Earth maintains its life-friendly temperature by reflecting, absorbing, and re-emitting just the right amount of solar radiation. To maintain a certain average global temperature, the Earth must emit as much radiation as it absorbs. If, for example, increasing concentrations of greenhouse gases like carbon dioxide cause Earth to absorb more than it re-radiates, the planet will warm up.

Not really all that controversial, you'd think.  But no, MacLeod implies that the atmosphere isn't keeping us warm, it's keeping us cool by protecting us from the boiling hot inferno of space:

The Sun has a surface temperature of 5778 Kelvin and emits of the order of 63,290,000 Wm-2 over every square metre of the photosphere.  By the inverse square law this staggering power is reduced to ~1368 Wm-2 at the distance the Earth is from the Sun...  A simple Stefan-Boltzmann calculation establishes this radiation power is capable of easily boiling water at Earth’s orbit – ~120 degrees C.  Even as far away as Mars the solar radiation is capable of inducing a temperature of ~319 Kelvin or ~46 degrees C in any object that absorbs significant quantities of it.

He then sneers, "Are the people who write gobbledygook like [the NASA publication] simply too stupid to describe or are they deliberately practicing misinformation to bolster a hypothesis?"

Which sounds like it could have come directly from the Unintentional Irony Department, because he is bolstering his own hypothesis by applying the Stefan-Boltzmann law incorrectly.

As he could have found out by taking a physics class -- or failing that, with a simple Wikipedia search -- in order to correctly calculate the energy budget of the Earth, you have to take into account that the Earth is a sphere.  He applied the law as if the Earth was a flat disk, and (unsurprisingly) got the wrong answer.  If you apply the law correctly, you come up with an average temperature of 6 °C -- so he was not only wrong, he was wrong by a factor of 20.

And yes, you read that right.  A climate change denier who calls the folks at NASA"simply too stupid to describe" apparently thinks that the Earth is flat.

The sad part is that this kind of specious reasoning (if I can even dignify it with that term) convinces people.  Almost no one has the expertise to recognize his argument as wrong on first reading; regrettably few think to check what he's saying against actual science.  All too many people see science-y words ("Ooh!  Stefan-Boltzmann equation!  That sounds complicated!  He must be right.") and swallow the rest of the claim without question.

So instead, let's look at some real science, shall we?  Because on the same day that Mr. MacLeod wrote his absurd piece on Flat Earth physics, a paper was published in Nature that shows that the amount of anthropogenic heat energy being dumped into the oceans has doubled since 1997.  Study co-author Jane Lubchenco of the Oregon State University Marine Sciences department said, "These findings have potentially serious consequences for life in the oceans as well as for patterns of ocean circulation, storm tracks and storm intensity."

James Severinghaus, of Scripps Institute of Oceanography, was even more unequivocal: "This study provides real, hard evidence that humans are dramatically heating the planet."

So once again, the climate change deniers are throwing around scientific terms in order to prop up a viewpoint that is contradicted by all of the evidence, and flies in the face of the consensus of nearly 100% of the climate scientists themselves.

Further indication that when it's expedient, a confident-sounding fast-talker can induce people to believe damn near anything.

Follow the money

There is nothing like blatant hypocrisy to put me in a blood-boiling rage.

It's even worse when the hypocrisy is coupled with mealy-mouthed self-righteousness.  That puts me in a condition that calls to mind the word "apoplexy."

And as Exhibit A, I give you: Representative Lamar Smith of Texas, chairman of the House Committee on Space, Science, and Technology.

How Smith ended up in a leadership role in the oversight of scientific research is one of those mysteries that even the Peter Principle is insufficient to explain.  Whenever Representative Smith opens his mouth, he utters such moronic statements that you have to wonder how he successfully got out of grade school, much less how he got elected to public office.  This is the man who said in 2009,  "The greatest threat to America is not necessarily a recession or even another terrorist attack. The greatest threat to America is a liberal media bias."  He claimed in 2014 that the policy of allowing immigrants to achieve US citizenship by serving in the military -- a policy that has been in place since the country's founding, and the awarding of citizenship to Baron von Steuben by George Washington -- was "President Obama aiding and abetting an immigrant crime spree."

But on no topic has he as vividly illustrated an understanding of the world that would be sub-par for an eighth grader as on climate science.  Smith is a diehard climate change denier, and in fact wrote an op-ed piece in 2013 that contained the mind-boggling line, "Contrary to the claims of those who want to strictly regulate carbon dioxide emissions and increase the cost of energy for all Americans, there is a great amount of uncertainty associated with climate science."

I'm not sure in what BizarroWorld a near 100% consensus amongst climate researchers constitutes "a great amount of uncertainty," but that is evidently Lamar's viewpoint.

[image courtesy of NASA]

What is most appalling about all of this is that one of the rallying cries of the deniers is "follow the money" -- implying that the scientists are getting rich off of fat government research grants, so they have every reason to cook the data to make it look like the world is warming up.  If there was no anthropogenic climate change, Lamar suggests, the funds would dry up.  So the scientists are inventing an ecological crisis in order to feather their own nests.

You have to wonder how the scientists are also conspiring to make the glaciers melt, surface seawater heat up, and creating an El Niño that is shaping up to the the most powerful one since records have been kept.  Mighty desperate, those scientists, to go to those kinds of lengths.

But you haven't heard the most appalling part yet.  Lamar Smith, who brands climate scientists as self-serving liars who are making shit up so they can get money, is now threatening Kathryn Sullivan, the head of the National Oceanic and Atmospheric Administration, with a subpoena -- in a move that is hinted to be only the first of a sweeping attack on anyone influential who is researching anthropogenic effects on climate.

"NOAA needs to come clean about why they altered the data to get the results they needed to advance this administration’s extreme climate change agenda," Smith said, a statement that ranks right up there with "When did you stop beating your wife?" in the Heads-I-Win, Tails-You-Lose department.

Of course, there are people who are just tickled to pieces about Smith's campaign of harassment.  Robert E. Murray, head of Murray Energy, the largest privately-held coal mining company in the US, thinks that Lamar is just wonderful.  The climate researchers are "not telling hardly any truth" [sic] about what the global climate is doing.  The world is actually cooling off, Murray says, which I'm sure will be a tremendous relief to all of you who listened to the scientists when they said that 2015 is almost certain to be the hottest year ever, shattering all previous records by a considerable margin.

Don't listen to those damn ivory-tower thermometer-wielding geeks, Murray says.  "They’re crony capitalists.  They’re making a fortune off of you the taxpayer."

And if you're not already mad enough, guess who funded the gathering at which Murray dispensed his wisdom?  The Texas Public Policy Foundation, a "nonpartisan research institute" that is still completely nonpartisan and unbiased after receiving the bulk of its funding from Koch Industries, Crownquest Oil & Gas, AEP Texas, ExxonMobil, VF-Russia, Texas Western Energy Corporation, ConocoPhillips, Devon Energy, Chevron, and Henry Petroleum LP.

Speaking of following the money.

And outside, the world continues to warm, the ice caps continue to melt, and the weather continues to destabilize.  As we speak, the United Nations Conference on Climate Change is going on, a conference that is very likely to follow in the footsteps of the ones before it in accomplishing nothing -- because science research oversight in our country is being kept in a stranglehold by anti-science loons like Lamar Smith and his counterpart, James Inhofe of Oklahoma, another climate change denier who astonishingly enough has ended up chairing the Senate Committee on Environment and Public Works.

You know, by nature I'm an optimist.  I like to think that most of the time, most of us are doing the best we can to live according to our moral codes.  But when I find out about stuff like this, I start slipping over to the world of the conspiracy theorists, and that worries me.  I don't like to think that our country is being led by people who know full well that we're headed for an ecological catastrophe, and from a combination of greed, short-sightedness, and stupidity are willfully lying to the American people about it.

But increasingly, that's what looks like is happening.

All I need is the air that I breathe

I think my most common thought, while reading a lot of woo-woo writing, is "Learn some damn science before you pretend you know what you're talking about."

Okay, I know that sounds pretty arrogant of me, as if I always know what I'm talking about.  I don't; I make mistakes as often as the next guy.  But one thing I do try to do is research what I'm writing about, find out what science and experimentation have shown, before I launch off into thin air.

I use the "thin air" metaphor deliberately because of a website discovered by a student of mine, a frequent Skeptophilia contributor with a sharp eye for searching out nonsense.  And this time, she found a doozy.  The title of this website, "CO2 and Oxygen in Evolution of Air on Earth and Health," by itself caused some puzzled eyebrow-raising, but nothing like the actual content -- because its author, Artour Rakhimov, seems to be in serious need of basic training in human physiology.

The gist of this website is that all of the medical problems you've ever experienced were caused by having too much oxygen, and too little carbon dioxide, in your tissues.  Yes, you read that right.  Furthermore, we "hyperoxygenate" during times of high activity because we evolved during a time when there was less oxygen in the air, and we had to breathe harder.  Now, hyperventilation is killing us:

Appearance of the first vertebrates (about 550 millions years ago) and the development of prototypes of human lungs took place when air was made up of only about 1% O2, while having much higher percentage of CO2 (Maina, 1998), likely over 7%. Normal air today has many times more O2  (about 20%) and only a fraction of the CO2 (0.03%). However, our cells now still live in the air that existed hundred millions years ago: “But the cells of animals and humans need about 7 % CO2 and only 2% O2 in the surrounding environment. This is the way how our cells live: cells of the heart, brain, and kidneys” (Buteyko, 1977).

Yup.  We still live in "hundred million year old air."  That's why my knees hurt and I have sinus problems.

Anyhow, there we were, millions of years ago, happily consuming our "main nutrient" -- yes, this is what he calls carbon dioxide -- when along came plants to mess everything up:

However, the main parameter of our environment, our air, had dramatic change during later stages of our evolution due to advance of green life that transforms CO2 into O2 during photosynthesis.  We can see that air had dramatic change during evolution. It now has too much oxygen and almost no CO2. Hence, the chief parameter of our environment (we can survive for days or weeks with no water or food, but only for minutes with no air) became abnormal in its composition. It is only existence of our lungs that protected us from extinction. Nature could not anticipate this cardinal change in air, but it did provide us with the means for survival.

No, apparently he doesn't know that photosynthesis predated aerobic respiration as an evolved metabolic pathway.  How exactly our ancestors could have evolved to use oxygen before there were photosynthesizing organisms there to produce oxygen, I have no idea.  Nor do I know how they survived.  I have this strangely amusing image of dinosaurs crashing about in a completely plant-free ecosystem, gasping for breath, and cursing the fact that they'd appeared too soon.

In any case, now that we've established what the problem is, what do we do?   Well, Artour Rakhimov has the solution -- learn to breathe more slowly, or use a "Frolov Breathing Device" -- a thing that basically gets you rebreathing exhaled air.  Oh, and by the way, Rakhimov is selling "Frolov Breathing Devices."  Did I even need to mention that?

Could there be any truth to this?  The answer is "no."  Raising carbon dioxide levels in your blood is called "respiratory acidosis" (carbon dioxide in solution in your blood plasma creates a weak acid, carbonic acid, dropping the blood pH).  This, in turn, is the signal to your brainstem to speed up your breathing rate.  Put simply: carbon dioxide levels, via their effects on your blood pH, are how your body keeps track of how fast you need to breathe.  Slowing down your breathing, or rebreathing exhaled air, will just make you feel uncomfortable, and stimulate the unpleasant sensation that you need to breathe faster.

Don't believe me?  Check out sources here and here -- the latter source stating that humans start showing signs of hypercapnia (carbon dioxide toxicity) at an inhaled air concentration of 3%, and that at 7% -- the level recommended as healthy by Artour Rakhimov -- you will experience "labored breathing, headaches, tinnitus, as well as impaired vision... You are likely to become confused in a few minutes, followed by unconsciousness."

Rakhimov himself seems pretty confused on the topic.  Maybe he's been breathing too much carbon dioxide.

See why I yelled at my computer several times while reading all of this?  Of course, Rakhimov couldn't hear me, and it wasn't because of the tinnitus.  But still, I find the whole thing immensely frustrating, especially given the fact that this is hardly the only idiotic pseudo-medical idea out there -- in fact, I've got another one planned for Monday, to the effect that the problem isn't the air, it's the water.

It's got too little hydrogen in it.  Two hydrogens to one oxygen just isn't enough.

I can barely wait.