Halting the conveyor

Today we have three stories that are absolutely horrifying in juxtaposition.

The first is a paper that came out a couple of days ago in Nature, describing a study by Jade Bowling (of Lancaster University) et al.  It is an analysis of a strange and sudden change in the topography of the Greenland Ice Sheet that happened in 2014 -- a two-square-kilometer part of the sheet dropped by as much as eighty-five meters.  The question, of course, is what happened to all the ice that used to be underneath it.  And what Bowling et al. found was that it had melted -- that the underside of the Greenland Ice Sheet is riddled with subglacial lakes and rivers.  In this case, downstream of the collapsed region, a flood burst through the surface, and within ten days ninety million cubic meters of fresh water gushed out as the cavity emptied.

We usually think of the melting of the polar ice sheets as a gradual process, something like the way ice cubes slowly melt in your glass of tea in summer.  But what this study shows is that the process proceeds quietly -- until it doesn't.  The tipping point between a gentle trickle and a massive flood can occur suddenly, and be due to factors that are largely out of sight.

The second came out in the same issue of Nature, and has to do with a study of the paleoclimate by a team led by Pedro DiNezio of Colorado University - Boulder.  DiNezio and his collaborators looked at the Atlantic Meridional Overturning Circulation (AMOC), sometimes called the "Atlantic Conveyor."  The AMOC is an enormous ocean current, of which the Gulf Stream is only a part, moving a greater volume of water per second than all of the rivers of the world put together.  It is driven by the combined effects of evaporation (making the water saltier) and cooling as the current flows northward; both of these result in the water becoming denser, and south of Iceland it becomes dense enough to sink.  This draws more warm water northward -- and is why Ireland and the United Kingdom, which are on the same latitude as Alberta, have mild climates.

[Image licensed under the Creative Commons R. Curry, Woods Hole Oceanographic Institution/Science/USGCRP., OCP07 Fig-6, CC BY 3.0]

But freshwater intrusion, like the one the prior study considered, lowers the density of the surface water, eventually making it too fresh to sink.  This can slow down -- or halt entirely -- the AMOC.

The focus of the effects has usually been on northeastern North America and northwestern Europe, where that heat transfer slowdown would be expected to trigger a dramatic cooling similar to the sudden crash that initiated the Younger Dryas 12,900 years ago, during which a warming climate was plunged back into the freezer for over a thousand years.  But what the DiNezio et al. study considered was what happens to all that excess heat.  Just because we here in upstate New York would probably be freezing our asses off doesn't mean the rest of the world would be.  The heat energy, of course, doesn't just go away.

And what they found is that when the AMOC slows down, that heat remains in the tropics -- triggering a spike in temperature and a drop in rainfall near the equator.  "This is bad news, because we have these very important ecosystems in the Amazon," said DiNezio.  "The Amazon rainforest contains almost two years of global carbon emissions, making it a major carbon sink on Earth.  Drought in this region could release vast amounts of carbon back into the atmosphere, forming a vicious loop that could make climate change worse."

But of course, no story about climate change would be complete without some breaking news describing how the Trump administration is determined to make it worse.  Lee Zeldin, head of the Environmental Protection Agency (which should have its name changed to the Big Oil Protection Agency, because under his leadership they couldn't give a flying rat's ass about protecting the environment), has just announced the overturning of a 2009 declaration stating that carbon dioxide and other greenhouse gases endanger human health and welfare.

His justification?  What do you think it was?

"It cost Americans a lot of money," Zeldin said.

The declaration was the foundation of climate change regulation in this country, and the impetus for rules limiting emissions from cars, airplanes, and power plants.  If the "endangerment finding," as the declaration is called, is overturned. it gives corporations carte blanche to ignore previous guidelines and mandates.

Zeldin, of course, thinks this is just hunky-dory.  "This will be the largest deregulatory action in the history of America," he crowed.

Because short-term profit is apparently more in need of attention than the long-term habitability of the planet.

I wish I had a hopeful note to end on, but I don't.  The whole thing puts me in mind of a comment from a student in my Environmental Science class, maybe fifteen years ago.  The question I put to them was, "At what point do you think that the majority of Americans will be motivated to address climate change in a meaningful way?"

Her answer was, "It won't happen until average Americans are directly and harshly impacted by it.  When there's no food on the shelves in the grocery stores.  When the rivers dry up.  When the sea level rises enough to flood major coastal cities.  Until then, it's easier to pretend nothing's wrong."

Another student, aghast, said, "But won't it be too late at that point?"

She responded simply, "Of course it will."

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No guardrails

Ever since Donald Trump came on the political scene, bragging that he could shoot someone in full view on Fifth Avenue and not lose a single supporter, I and a lot of people on the leftish-side of things have wondered what it would take to get his followers to admit they'd been scammed by a career con-man who has zero moral code.

I think it was about a third of the way into the first Trump presidency that I realized he'd been, for once, telling the unvarnished truth.  I hear now and then of some Trump voter who publicly states that they've woken up and will never support him again, but I think they're very much the exception.  And I've long blamed it largely on the media; a study shortly after the election found that one of the strongest correlations to voting for Trump was lack of access to fact-based information.

So for a while, it was comforting to think that if only these people did have accurate information, they'd come to their senses.  But recently I've begun to think the situation is worse than that.

They know -- but they don't care.  There is no red line, no boundary he could cross that would make people say, "Okay, that's enough."

Since his re-election, Trump's behavior has become more and more unhinged, and instead of provoking a sense of "good lord, what have we done?", the reaction has been more, "Wheeeeee!"  In the last two weeks, the same man who said one of his top priorities was to get us out of military conflicts overseas has stated his intent to annex Greenland and Canada, invade Mexico, and retake the Panama Canal.  (And speaking of media complicity, CNN framed this story as "if he's serious, it'd be the biggest U.S. expansion since the Louisiana Purchase" rather than what any legitimate news source would say, which is, "fucking demented lunatic threatens our allies and risks international conflict with his unprovoked deranged saber-rattling.")

And the fact remains that he's still catastrophically ignorant.  He tweeted this image, apparently without having any idea that the Matterhorn isn't in Canada.

His supporters haven't batted an eyelash.  MAGA Republican Senator Marsha Blackburn said she was all in on taking back the Panama Canal, that "this is what Americans want to see."  Mini-Me, a.k.a. Eric Trump, thought it'd be a good idea to throw fuel on the fire, and posted this:

Next stop, the Sudetenland.

His supporters think Trump has some sophisticated plan here, but he's not playing three-dimensional chess.  He doesn't have the intelligence for tic-tac-toe, much less anything harder.  The Panama thing is most likely retribution, because businesses owned by Trump were recently shut down in the country after accusations of tax evasion and that they were being used as fronts for laundering drug money.  Strategy-wise, he's never progressed any further than "Thag hit me with rock, me hit Thag with rock."

It's why he's threatening to jail Liz Cheney, Anthony Fauci, Mark Milley, and Alexander Vindman.  They committed the cardinal sin of standing up to him, of calling him out on his lies, of demanding that he be held to the same standards of justice as anyone else in the country.  Anyone who dares to point out the Emperor Has No Clothes needs to be silenced by whatever means necessary.

But despite all this, his followers are still cheering -- and lambasting anyone who dares to contradict Dear Leader.

It's gotten so bad that even when one of Trump's favorites -- former Florida Representative Matt Gaetz, once nominee for Attorney General -- was credibly shown to have paid for sex, committed statutory rape, and gone on drug-fueled binges, the response by his supposed family-values followers was not to say, "this guy should be locked up," but to circle the wagons and claim Gaetz had been framed.

Lie after lie, grift after grift.  And yet -- somehow -- it's worked, and is still working.  He scams people in broad daylight, and his followers eagerly line up to be taken advantage of.  The evangelical Christians, who are somehow still behind him one hundred percent despite the fact that he embodies all Seven Deadly Sins in one individual, are just thrilled to pieces by the fact that he's hosting a pre-inauguration prayer service and allowing supporters to attend -- for $100,000 each.

"Pay-to-pray," it's being called.  

I may be off-base, here, being an atheist and all, but isn't this the sort of thing that caused Jesus himself to get violent?  Something about using a whip on money-lenders in the Temple, if I remember correctly.

I think the bottom line is that we on the other side of things have made the mistake of thinking this behavior is rational.  That somehow, if we argue, if we just present more information, use logic and facts, people will be convinced.  The truth is, what's happening here is fundamentally irrational; it's precisely the same appeal to emotion, anger, and nationalism that happened in Germany in the 1930s.  Just like Hitler did, Trump is taking the legitimate concerns of struggling citizens -- anger and anxiety over high cost of living, poor access and high cost of health care, lack of decent-paying jobs with benefits, concerns about crime rate -- and twisting the aim to focus on the wrong causes.  Trump's biggest allies are the super-wealthy corporate leaders, so at all costs we can't have them become the targets.  Instead, get the blame pinned on minorities, immigrants, liberal Democrats, non-Christians, LGBTQ+ people.  

It's why alleged CEO-killer Luigi Mangione has them so freaked out.  For a moment, it forced the attention back on corporate billionaires as a fundamental piece of what's wrong in the United States.

But don't expect the focus to stay there.  It's back to distract, distract, distract.  I don't think we're actually going to invade Greenland, Canada, Mexico, or Panama; Trump has the attention span of a toddler who just had eight Milky Way bars for lunch.  And in any case, actually accomplishing any of that was never the goal.  The real goal is to get Americans to stop thinking, and back to treating everything Trump says as the de facto gospel truth.

He knows that if in two years he hasn't followed through on a single one of his campaign promises, much less any of his idle threats, none of his followers will care -- or even remember.

There is no red line, no guardrails, no brakes, no point where the people who back him will say "enough."  Waiting for it to happen is a fool's errand.  We have to resist, we have to continue to fight, but the war won't be won through logical argument.

It's probably crossed your mind to wonder why, if I think the Trump voters are that unreachable through reasoning, I'm bothering to write this.  It's a valid question.  Besides just processing my own anger, for me it's also a way to connect with like-minded folks, to reassure them that there still are sane people in the world.  To quote British philosopher Edmund Burke, "When bad men combine, the good must associate; else they will fall, one by one, an unpitied sacrifice in a contemptible struggle."

Or as Benjamin Franklin put it, more succinctly and more pointedly: "We must all hang together, or we shall most assuredly all hang separately."

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Bell ringer

Sometimes we dodge a bullet.

In September of 2023, seismologists all over the world recorded an odd periodic signal that lasted about nine days.  It was strongest in Europe and eastern North America, but was recorded in places far distant.  The first pulses of the signal had the highest amplitude, and it gradually faded in intensity afterward; the effect was very much like the sound waves generated by a struck bell, which begin loud and eventually diminish into silence once the metal stops vibrating.

It took a while for the geologists to figure out what caused the signal, and when they did, it caused a few gasps -- and then sighs of relief.

The climate-change-induced warmup in the polar regions has caused a huge loss of ice mass in Greenland and Antarctica, and the main associated hazard we've been warned about is sea level rise.  But the September 2023 event highlights another potential problem.  The source of the seismic signal was the collapse of a 1.2-kilometer-high mountain peak into remote Dickson Fjord in Greenland, triggered by the thinning of an ice wall that had held back the rock and debris.  When the estimate 25 million cubic meter landslide hit the water, it triggered a tsunami over a hundred meters high that proceeded to slosh back and forth across the fjord about once every ninety seconds, creating a vibration in the Earth's crust that was picked up on seismometers thousands of kilometers away.

Dickson Fjord, Greenland [Image licensed under the Creative Commons Bjoertvedt, Dicksonfjorden IMG 8800, CC BY-SA 3.0]

The reason I call this "dodging a bullet" is twofold.  First, Dickson Fjord is far away from human settlements; the only damage was to an at-the-time-unoccupied patrol station on Ella Ø, an island seventy or so kilometers away, where the tsunami height was about four meters.  Second, Dickson Fjord is narrow, with a lot of twists and turns, so most of the energy of the tsunami was expended by the sloshing of water back and forth across the inlet; little of the energy made it out of the mouth of the fjord into the north Atlantic.

The analysis of the seismograph data, and their cause, were the subject of a paper in Science this week.

"When I first saw the seismic signal, I was completely baffled," said Stephen Hicks, geologist at University College London, who co-authored the study, in an interview with Science Daily.  "Even though we know seismometers can record a variety of sources happening on Earth's surface, never before has such a long-lasting, globally-traveling seismic wave, containing only a single frequency of oscillation, been recorded.  This inspired me to co-lead a large team of scientists to figure out the puzzle.  Our study of this event amazingly highlights the intricate interconnections between climate change in the atmosphere, destabilization of glacier ice in the cryosphere, movements of water bodies in the hydrosphere, and Earth's solid crust in the lithosphere.  This is the first time that water sloshing has been recorded as vibrations through the Earth's crust, traveling the world over and lasting several days."

It's sobering to think of what would have happened had the landslide occurred in a cliff facing the open ocean, and not in a narrow, remote fjord.  Without anything to damp the oscillations and act as a shock absorber to dissipate the energy of the landslide, the displaced water would have created an unimpeded tsunami that might have wrought havoc on populated coastlines.

We lucked out.

Addressing climate change should be a priority not only for the obvious reasons -- mitigating extremes of weather, slowing down sea level rise, and minimizing the impacts on biodiversity and agriculture.  But the warming Earth increases our risks of other, more sudden and unexpected, hazards, ones that are impossible to predict and therefore way harder to protect ourselves against.  Decreasing our reliance on fossil fuels isn't going to be an easy fix, but in the long run, the dangers of accelerating climate change far outweigh the problems created by our efforts to slow it down.

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The microcontinent

One of the nice things about science is that it allows us to understand the parts of the universe that are beyond common sense.  

Don't get me wrong, common sense is often a decent guide to figuring things out, and there's some truth to the lament that it'd be nice if it were more common.  The problem is, our intuitive grasp of how stuff works evolved in the context we live in -- moderate sizes and masses, moderate speeds, and moderate time durations.  Get very far out of that context, and common sense can give you the wrong answer.  One of the first times I ran into this was in high school physics, where I learned the startling fact that an object's vertical and horizontal velocity are entirely independent of each other.  This is illustrated by the oft-quoted example that if you fire a bullet horizontally, and at the same time drop a bullet from the height of the gun's barrel, the two bullets will hit the ground at precisely the same time (assuming level terrain).  It may seem counterintuitive, but it's true -- and it took Isaac Newton to show why that was.

We run into problems not only when we deal with things moving quickly, but when they're moving slowly -- so slowly they appear not to be moving at all.  I got to thinking about this when I was sent a link by my friend, the awesome author Andrew Butters (you should follow him at the link provided, and also immediately order his phenomenal new novel Known Order Girls, which is one of the most poignant books I've ever read).  Andrew is, like me, a science nerd -- we were both drastically unsuccessful physics majors in college, who despite that experience maintained a deep fascination with how the universe works.  (Interestingly, our comeuppance as incipient scientists came in different classes.  His nemesis was Electromagnetic Theory, and mine was Classical Mechanics.  In both cases we passed the class largely because the professor didn't ever want to see our names on his roster again, and afterward we both decided that maybe a career as a physicist was not in the cards.)

In any case, this time the topic he sent me was geology -- in particular, plate tectonics, a particular interest of mine.  Researchers have just found that a part of Nunavut, Canada is actually a microcontinent -- a geologically-anomalous piece of continental crust that came loose from Greenland and welded itself to North America on the other side of the Davis Strait.  

The Davis Strait and the west coast of Greenland [Image licensed under the Creative Commons brewbooks via Flickr (CC BY-SA 2.0)]

What's curious about this is that up until about 45 million years ago, Canada and Greenland had been moving apart.  The evidence is that there was a rift zone -- that's what formed the Davis Strait in the first place -- and that some time in the Mid-Eocene Epoch, the rift failed.  (This is not that uncommon; there's a good possibility that the Cameroon Line and the New Madrid Fault are both failed rift zones.)  In any case, after the Davis Strait Rift sealed back up, Greenland started moving in tandem with the North American Plate -- except for a piece of it that sheared off and stuck to what is now Canada.

"The reinterpretation of seismic reflection data offshore West Greenland, along with a newly compiled crustal thickness model, identifies an isolated terrane of relatively thick (19–24 km [12-15 miles]) continental crust that was separated from Greenland during a newly recognised phase of E-W extension along West Greenland’s margin," the team wrote.  "We interpret this continental block as an incompletely rifted microcontinent, which we term the Davis Strait proto-microcontinent...  As our seismic reflection interpretations indicate an extensional event in the eastern Davis Strait between 58 and 49 Myr, spatially coincident with the zone of thinnest continental crust between the continental fragment and Greenland, we infer this extensional event [rift] led to the separation of this fragment from Greenland."

When you think about it, it's unsurprising that it took so long for geologists to figure plate tectonics out.  Despite such broad hints as the puzzle-piece outlines of South America and Africa, a process this slow is not obvious.  Add to that the fact that this particular plate is in one of the most inhospitable places on Earth, accessible to researchers for maybe two months a year (that's being generous.)  The entire picture is still being pieced together.  Our tectonic map is pretty good, but the new research shows us that we don't have it all parsed quite yet.

Which is the way it should be.  As Neil deGrasse Tyson put it, the more we learn, the more we extend the perimeter of our ignorance.  And this, after all, is what drives science -- the fact that every question we answer brings up a dozen more.

I think we'll be working at this for quite some time to come.

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Meltdown

With the insane weather we've had this summer -- and which is showing no signs of calming down -- it's easy to forget about another inevitable outcome of anthropogenic climate change: sea level rise.

Part of the issue, of course, is that humans have a regrettable tendency only to pay attention to what's right in front of their faces, like the current worldwide extreme heat wave.  It's why researchers found in 2014 that public concern about climate change decreases during the winter, an attitude Stephen Colbert summed up as "I just had dinner, so there's no such thing as world hunger."

And sea level rise is so gradual you really do have to have a long baseline even to notice it.  It's only in extremely low-lying places like Louisiana's Isle de Jean-Charles that people have been forced to notice -- and that only because the place looks very likely to cease to exist entirely in the next ten years.

Another reason the (well justified) panic over climate change has mostly focused on extreme high temperatures on land and hot sea surfaces fueling bigger storms is that climatologists thought we had something of a buffer, ice-melt-wise, in the Greenland Ice Sheet.  The Greenland Ice Sheet, they thought, had been unmelted for millions of years, which not only kept all that water locked up in solid form on land, but also helped stabilize the Arctic climate.

Note my use of the past tense.

[Image licensed under the Creative Commons Christine Zenino from Chicago, US, Greenland Glaciers outside of Ammassalik (5562580093), CC BY 2.0]

New research, based on an ice core that had been collected in the 1960s but then lost for nearly sixty years, showed something terrifying: four hundred thousand years ago, nearly the entire Greenland Ice Sheet melted, raising the sea level by several meters -- at a time when the carbon dioxide concentration was lower than it is today.  Using something called a luminescence signal -- a highly-sensitive technique that measures the last time flakes of feldspar or quartz were exposed to light, and therefore were on the surface -- the researchers found what they are calling "bulletproof" evidence that layers thought to be continuously buried deep in the Greenland ice were exposed between 420,000 and 370,000 years ago.

If this happened today -- and the indications are that if we don't curb climate change fast, it will -- the results will be nothing short of catastrophic.

"If we melt just portions of the Greenland ice sheet, the sea level rises dramatically," said Tammy Rittenour, climatologist at Utah State University.  "Forward modeling the rates of melt, and the response to high carbon dioxide, we are looking at meters of sea level rise, probably tens of meters.  And then look at the elevation of New York City, Boston, Miami, Amsterdam. Look at India and Africa -- most global population centers are near sea level."

Considering that the average elevation of the state of Delaware is twenty meters -- and that Louisiana and Florida tie at thirty-three meters -- this should scare the absolute shit out of everyone.  (And like Rittenour said -- even in those low-elevation states, most of the population is still along the coast -- so even a meter or two rise would be catastrophic.)

And, typical of privileged people in industrialized countries, I've focused on where I live.  If you look at the top ten cities threatened by climate change, only one (Miami, Florida) is in the United States.  Two are in India (Kolkata and Mumbai), two are in Vietnam (Ho Chi Minh City and Hai Phong), two are in China (Guangzhou and Shanghai), and one each in Bangladesh (Dhaka), Myanmar (Rangoon), and Thailand (Bangkok).  Just counting the urban population of these ten cities puts almost seventeen million people with the choice of relocating or drowning.

You think the refugee problem is bad now?  

And I'm not just talking about the dreaded "caravans of foreign refugees" the right-wingers here in the U.S. like to bring out every time there's focus on the fact that their entire platform lately has consisted of denying rights to people they don't like.  If the sea level rises even by a meter or two, every coastal city in the United States is in trouble -- so we're gonna have an internal refugee problem the likes of which we've never seen before.

People, we have got to figure this out.

We've had enough time to process it all, to come to the conclusion that yes, it's real, and no, it's not a "natural warm-up."  I'll end with a quote from British science historian James Burke's brilliant (and prescient) documentary After the Warming, which aired all the way back in 1989: "People spend money to insure their homes, their health, and their lives against far less likely occurrences.  That's all legislation to stop climate change turns out to be: planetary insurance...  Our attitude thus far has been like the guy in the old joke, have you heard it?  A man falls off the top of a twenty-story building, and someone on the seventeenth floor sticks his head out of the window and asks the guy how he's doing.  The man shrugs as he falls and says, 'So far, so good.'"

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Relics of the distant past

Today we'll stay in an archaeological vein, mostly because a couple of loyal readers of Skeptophilia read yesterday's post and responded with links of their own and messages which basically boil down to, "Yes, but have you seen this?"

The first one comes to us from the ever-entertaining site Mysterious Universe, but unlike their usual fare of Bigfoots and UFOs, this one is about legitimate scientific research.  Not that you could tell from the title, which is "Yorkshire's Atlantis May Have Finally Been Found."  To be fair, the appellation of "Atlantis" isn't the fault of the author, Paul Seaburn; apparently this site, Ravenser Odd, has been called that before.  But unlike Atlantis, Ravenser Odd is a real place.  It was a port city on the estuary of the River Humber, attested thoroughly in records of the time until in 1362 there was a storm that breached the sand-based seawall and swamped it completely, and the once thriving town -- like its mythological namesake -- sank beneath the waves.

The shape of the long, narrow seawall is what gave the place its name, all the way back in Viking times, some four hundred years earlier; Ravenser Odd is a mangled version of hrafns eyr, which means "raven's eye" in Old Norse.  In its time it was a busy place.  It was one of the most thriving ports in the region, and a record from 1299 describes it as containing a central marketplace, wharves, warehouses, a court, a prison, a chapel, two mills, a tannery, an annual fair, and over a thousand residences.  The coastal region near the original submerged town retained the name, and in fact it's mentioned twice in Shakespeare, where he calls it "Ravenspurgh" (Richard II, act 2, scene 1, line 298, and Henry IV Part 1, act 1, scene 3, line 245).

Despite multiple attestations in the records, no one was able to find where the original Ravenser Odd had stood -- until now.

An amateur archaeologist named Philip Mathison, who is something of an expert on Ravenser Odd, stumbled upon an 1892 document on eBay that mentioned "submarine remains" at Spurn, a tidal island north of the mouth of the Humber -- and gave directions on how to find them.  Mathison went out in a boat with an echo sounder, and found what looked like a human-made rock wall, exactly where the document had said it would be.

"People had assumed it was way out to sea, as the shape of the peninsula now is very different to how it was in the thirteenth century," Mathison said.  "This document showed a stone ledge to the east of Spurn which I believe could be the walls of a dock or quay... The ridge was most likely rock armor to protect the port, as it was under threat from erosion way before it was abandoned.  The bulk of the town's buildings were on a shingle bank called The Old Den, to the west side of Spurn, and some brickwork from them has been found in the past.  The town curved around like a fish hook and the wharves were at the other end... But it needs a proper dive to find out."

Seems like Mathison is going to get his wish -- two archaeologists from the University of Hull have already purchased scanning equipment and obtained funding for other supplies for an expedition this summer, when the weather in the North Sea improves.

Also with a Viking connection is a study done at the University of Massachusetts - Amherst that seems to upend a long-held theory about why the Norse settlements of Greenland died out in the late fourteenth century.  Previous models had attributed the collapse to the onset of the Little Ice Age, a worldwide drop in global average temperature that (among other things) caused the Greenland sea access to freeze up year round and made it an even more miserable place to live than it already is.  But the new study -- using two organic molecules as markers that are known to indicate, respectively, temperature and water availability -- showed that during the period of the collapse, the temperature didn't drop much, but it became significantly drier.

The harsh winters were one thing, but when the rain stopped falling even in the warmest months of summer, that was the kiss of death for the crops and domesticated animals at the Norse settlements, and ultimately, the Norse themselves.  

For the last story, we return to the British Isles, where a geophysical survey near the town of Aberlemno uncovered a 1.7-meter-long stone carved with designs identified with the Picts, the mysterious people who inhabited northern and eastern Scotland before the Dál Riada Scots moved in and kind of took over in the tenth century.  There aren't many Pictish records around; they were Celtic, but appear to have spoken a Brythonic language related to Welsh, Cornish, and Breton, not a Goidelic language like Gaelic, Irish, and Manx.

The discovery was made quite by accident.  While moving some surveying equipment, they noticed some anomalies that seemed to indicate the buried foundation of a settlement.  They dug into the soil, and hit a rock. "I just brushed my hand, and there was a symbol," said Zack Hinckley, an archaeologist at the University of Aberdeen.  "And we had a freakout... there were genuine tears."

The Pictish stone from Aberlemno, Scotland

The difficulty is that given the paucity of Pictish records, little is known of the script, and it's currently unknown whether these were written language, or simply decorative symbols.  The stone has been removed to an archaeological conservation lab in Edinburgh for further study.

So there you are.  The world of archaeology has been hopping lately.  It's always amazing to me that despite the extensive research that's been done, with state-of-the-art mapping and surveying tools, that there are still plenty of astonishing artifacts out there to find.

Some of them, apparently, right underneath our feet.

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Cliffs of ice and rivers in the sky

One of the most frustrating things is that instead of meeting the challenges we have and then moving forward, we seem to be fighting the same battles over and over and over.  It's like running on a treadmill, except instead of getting aerobic exercise, all you get is high blood pressure and an ulcer.

It will come as no surprise that I'm once again referring to anthropogenic climate change, which has such a mountain of evidence behind it that there is no argument any more.  Or there shouldn't be.  But all it takes is Some Guy On The Internet making a comment that amounts to "Nuh-uh, is not," and all of the science deniers give him a standing ovation and say, "See, we told you."

The latest in the long line of unqualified anti-science types acting as if their pronouncements somehow outweigh actual research is a tweet from Matt Thomas claiming that the eruption of Mt. Merapi in Indonesia in 2020 exceeded all of the human-generated carbon dioxide ever emitted.  Thomas said, "This volcano just spewed more CO2 than every car driven in history.  Climate change is natural.  Taxing us into poverty isn’t the answer."

Despite the fact that this isn't just false, it's false by several orders of magnitude, it immediately started a Greek chorus of "Climate change is a hoax!" from all the self-appointed climatologists on Twitter.  The tweet got over a hundred thousand likes, and the video link he provided got millions of views.  I've seen it posted on social media dozens of times myself, always to shouts of acclamation.  Very few people responded the way I did, which was to say, "You, sir, are a dangerous idiot."  It seems like a lot of the people who actually trust science have been wearied to the point of exhaustion, and we're just not taking the bait any more.

And it's not like the numbers aren't out there to confirm Thomas's dangerous idiocy.  Anyone with a computer and access to scientific databases on the internet can check his figures, and see that he's not just in left field, he's so far away he couldn't see left field with a powerful telescope.  In an average year, all the volcanic activity in the world releases about 0.3 gigatons of carbon dioxide; the carbon dioxide released in one year from vehicular exhaust is ten times higher than that.  (Note that this is all the emissions from all the volcanoes in a year, as compared to vehicular emissions in a year; Thomas was claiming that one volcano exceeded the emissions of all the automobiles ever created.  I guess if you're gonna lie, you may as well make it a doozy.)

So instead of trusting Some Guy On The Internet, let's look at what the actual science is saying.  How's that for a novel idea?

Just last week there were three studies that in a sane world, would alarm the hell out of everyone, but for some reason, have barely caused a blip on the radar.

First from the University of Tsukuba (Japan), we have a study showing that a scary meteorological phenomenon called an atmospheric river is predicted to spike in frequency, especially in east Asia.  Atmospheric rivers are pretty much what they sound like; narrow, fast-moving bands of extremely humid air, that undergo what's called adiabatic cooling when they run into land that has a higher elevation.  This forces the air upward, causing the volume to expand and the temperature to drop -- and all of that moisture condenses as rain or snow.

We're not talking insignificant amounts of water, here.  An atmospheric river, propelled by a typhoon a thousand kilometers to the east, struck Henan Province in China last year.  The amount of rainfall they received is, honestly, hard to imagine.  In three days the city of Zhengzhou got sixty centimeters of rainfall -- about equal to its average annual precipitation.  In some places in the region, the rainfall rate exceeded twenty centimeters per hour.  Over three hundred people died in the floods, and the damage was estimated at twelve billion dollars.

And this phenomenon isn't limited to east Asia.  Want it brought home to you, Americans?  This same phenomenon has been known to strike other places with strong on-shore air currents driving into lowland areas bounded by steep climbs in elevation -- like the Central Valley of California.

The second study is from the Alfred Wegener Institute in Germany, and found that current models support that Greenland -- one of the world's largest repositories of land-bound ice -- has a delayed response to warming.  Meaning that even if everyone suddenly wised up and cut greenhouse emissions and the temperature stabilized, the Greenland Ice Cap would continue to melt.

For centuries.

The response of Some Guy On The Internet to this was a viral YouTube video showing an ice cube melting in a cup of water, wherein the water level in the cup did not change, captioned,  "A little science lesson for the IDIOTS at the global warming conference," once again to rousing applause, despite the fact that this particular SGOTI neglected the fact that the meltwater that matters is from ice that starts out on land.

That almost no one raised this objection makes me despair for the state of science education in American public schools.

Scariest of all was the study presented at the annual meeting of the American Geophysical Union warning that the Thwaites Glacier -- an on-land mass of ice about the size of Florida -- is in imminent danger of collapse.  And I do mean imminent; we're not talking "by 2100."

The prediction is that the collapse could come some time in the next three to five years.

The leading edge of Thwaites Glacier [Image is in the Public Domain courtesy of NASA]

What's going on is that Thwaites is held back by a floating ice shelf, the bottom of which is caught against the top of an undersea mountain.  The recent study looked at the rate of warm water infiltration and melting on the underside of that ice sheet, and found that the area of ice that's caught -- the part that's providing the friction holding the whole thing in place --  has decreased drastically.  It's like putting a chuck underneath the tire of a car in neutral sitting on an incline.  It doesn't move -- until you remove the chuck.  After that, the car rolls forward, and continues to accelerate.

If the ice sheet holding Thwaites back buckles, the entire glacier will start to slide.  Dumping this much ice into the ocean will raise sea levels by something on the order of sixty centimeters, inundating coastlines and low-lying areas and displacing millions of people.

Although the studies have improved in terms of detail, none of this is new information.  Scientists have been sounding the alarm for decades.  Increasingly they're taking the role of Cassandra -- the figure from Greek myth who was blessed with the ability to see the future, but cursed to have no one believe her.  The situation isn't helped by deliberate anti-science propaganda from the corporations who stand to lose financially if fossil fuels are phased out, and "news" services who are funded by those same corporations.

And, of course, by a populace who has been brainwashed to pay more attention to Some Guy On The Internet than to the hard data and sophisticated models generated by trained scientists.  But wearing blinders only works for so long.

Once you're up to your neck in sea water, it will be a little hard to argue that the scientists have been lying all along.

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Since reading the classic book by Desmond Morris, The Naked Ape, when I was a freshman in college, I've been fascinated by the idea of looking at human behavior as if we were just another animal -- anthropology, as it were, through the eyes of an alien species.  When you do that, a lot of our sense of specialness and separateness simply evaporates.

The latest in this effort to analyze our behavior from an outside perspective is Pascal Boyer's Human Cultures Through the Scientific Lens: Essays in Evolutionary Cognitive Anthropology.  Why do we engage in rituals?  Why is religion nearly universal to all human cultures -- as is sports?  Where did the concept of a taboo come from, and why is it so often attached to something that -- if you think about it -- is just plain weird?

Boyer's essays challenge us to consider ourselves dispassionately, and really think about what we do.  It's a provocative, fascinating, controversial, and challenging book, and if you're curious about the phenomenon of culture, you should put it on your reading list.

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

Caught in the sea's net

The specter of climate change is getting difficult to ignore.  While you still can't point at a particular event and say "that happened because of anthropogenic climate change" -- as I said about a million times to my students, "climate isn't the same as weather" -- we've had enough anomalous heat waves, droughts, floods, and storms in the past ten years that it's getting harder and harder to deny unless you go around with blinders on or are just plain stupid.  (The latest being the catastrophic tornadoes that tore through Kentucky a couple of weeks ago, despite it being December, usually a low point in tornado occurrence and intensity.)

There are signs that even the science deniers are beginning to have some traces of second thoughts about the whole thing.  A study in Nature Scientific Reports a few weeks ago found that "climate contrarians" have of late begun to shift their ground, from outright denial that it's happening to attacking the researchers' integrities and the solutions they propose.  While this is still maddening to those of us who can actually read and understand a scientific paper, it's at least a tentative step in the right direction.  "I don't like the people who are saying this" and "the solutions won't work/are too expensive" are better than "this isn't happening" and "la la la la la la la not listening."

But the evidence that the situation is perilous keeps piling up.  One of the consequences of climate change most people don't think a lot about is sea level rise, mostly because the numbers seem insignificant; for example, a recent study showed that in the twenty-seven years between 1993 and 2020, the average sea level rose by a centimeter, and the rate of rise in the past ten years is triple what it was in the twentieth century.

It's easy to say, "a centimeter?  That's hardly anything."  But that ignores a couple of things.  First, that's an average; because of patterns of melt water, and sea and wind currents, some places have seen an increase of up to twenty centimeters, easily enough to cause devastating coastal flooding and infiltration of fresh-water aquifers with salt.  Second, there's geological evidence that when the sea level rises, it can happen in fits-and-starts, as ice shelves (primarily in Greenland and Antarctica) collapse.  Given how many people live in low-lying coastal areas, it wouldn't take much to cause a humanitarian catastrophe.

Another pair of studies that came out just last week have illustrated how vulnerable coastal communities have been -- and still are -- to changes in sea level.  Archaeologists uncovered evidence from two millennia ago in southern Brazil indicating that a drop in sea level due to increases in polar ice exposed shellfish beds that the coastal indigenous people depended on, and led to wide abandonment of settlements in the area.  The opposite happened in Greenland in the fourteenth century -- coastal communities that had been settled by Vikings three centuries earlier got swamped, eradicating coastline and driving the settlers up against uninhabitable glacial regions.  They were caught between the rising seas and the rising ice, trapped in an ever-shrinking strip of land that eventually disappeared completely.

[Image licensed under the Creative Commons Jensbn, Greenland scenery, CC BY-SA 3.0]

My initial reaction to the latter paper was puzzlement; the fourteenth century was the height of the Little Ice Age, so you'd think the freeze-up would have lowered sea level, not raised it.  But I was failing to take into account isostasy, which is the phenomenon caused by the fact that the continents are literally floating in the magma of the mantle.  Just like adding weight to a boat causes it to ride lower in the water, adding weight to a continent causes it to sink a little into the mantle.  So when the ice sheets built up on Greenland, it pushed it downward, submerging habitable coastline.  (The opposite has happened as the glaciers have melted; in fact, it's still happening in Scandinavia, Canada, and Scotland, the latter of which is still undergoing isostatic rebound at a rate of ten centimeters of uplift per century.)

The deniers are right about one thing; the Earth has certainly experienced climatic ups and downs throughout its long history.  What's terrifying right now is the rate at which it's happening.  A study from the International Panel on Climate Change found persuasive evidence that the rate of temperature increase we're seeing is higher than it's been since the Paleocene-Eocene Thermal Maximum, over fifty million years ago.

If that doesn't scare you, I don't know what would.

It's the humanitarian cost that's been on my mind lately, not just because of today's climate change, but the changes that have occurred historically.  I was so captivated by the tragedy of the disappearance of the Norse settlements in Greenland that years ago, it inspired me to write a poem -- one of the few I've ever written.  What would it be like to be the last person alive in a place, knowing no one would come to rescue you?  I can only hope humanity's fate won't be so bleak -- but whenever I think about our reckless attitude toward the environment, this haunting image comes to mind, and I thought it would be a fitting way to end this post.

Greenland Colony 1375

He goes down to the sea each day and walks the shore.
Each day the gray sea ice is closer, and fewer gulls come.
He wanders up toward the village, past the empty and ruined rectory.
The churchyard behind it has stone cairns.  His wife lies beneath one,
And there is one for Thórvald, his son,
Though Thórvald's bones do not rest there; he and three others
Were gathered ten years ago in the sea's net
And came not home.

Since building his son's cairn,
He had buried one by one the last four villagers.
Each time he prayed in the in the stone church on Sunday
That he would be next,
And not left alone to watch the ice closing in.

In his father's time ships had come.  The last one came
Fifty years ago.
Storms and ice made it easy for captains to forget
The village existed.  For a time he prayed each Sunday
For a ship to come and take him to Iceland or Norway or anywhere.
None came.  Ship-prayers died with the last villager,
Three years ago.  He still prayed in the stone church on Sunday,
For other things; until last winter,
When the church roof collapsed in a storm.
The next Sunday he stayed home and prayed for other things there.

Now even the gulls are going,
Riding the thin winds to other shores.  Soon they will all be gone.
He will walk the shore, looking out to sea for ships that will never come,
And see only the gray sea ice, closer each day.

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I remember when I first learned about the tragedy of how much classical literature has been lost.  Take, for example, Sophocles, which anyone who's taken a college lit class probably knows because of his plays Oedipus Rex, Antigone, and Oedipus at Colonus.  He was the author of at least 120 plays, of which only seven have survived.  While we consider him to be one of the most brilliant ancient Greek playwrights, we don't even have ten percent of the literature he wrote.  As Carl Sagan put it, it's as if all we had of Shakespeare was Timon of Athens, The Merry Wives of Windsor, and Cymbeline, and were judging his talent based upon that.

The same is true of just about every classical Greek and Roman writer.  Little to nothing of their work survives; some are only known because of references to their writing in other authors.  Some of what we do have was saved by fortunate chance; this is the subject of Stephen Greenblatt's wonderful book The Swerve, which is about how a fifteenth-century book collector, Poggio Bracciolini, discovered in a monastic library what might well have been the sole remaining copy of Lucretius's masterwork De Rerum Natura (On the Nature of Things), which was one of the first pieces of writing to take seriously Democritus's idea that all matter is made of atoms.

The Swerve looks at the history of Lucretius's work (and its origin in the philosophy of Epicurus) and the monastic tradition that allowed it to survive, as well as Poggio's own life and times and how his discovery altered the course of our pursuit of natural history.  (This is the "swerve" referenced in the title.)  It's a fascinating read for anyone who enjoys history or science (or the history of science).  His writing is clear, lucid, and quick-paced, about as far from the stereotype of historical writing being dry and boring as you could get.  You definitely need to put this one on your to-read list.

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

The rising waters

2020 has become some kind of nihilist joke.  How many versions of the "2020 Apocalypse Bingo Card" have you heard?  And it does seem like things are just piling on.  Right now, we have a major category-3 hurricane bearing down on southern Louisiana -- that just got hit by a totally different tropical storm three days ago.  We're in the middle of a pandemic that is showing no signs of letting up.  There are record-setting wildfires in California.  The economy is giving serious signs of tanking in a big way.  Protests against police brutality seem to erupt every other day.  Last, we're in the middle of the Republican National Convention, where the platform seems to be, "Look how fucked up everything has gotten in the last four years!  Give us another four and we'll do the same thing again but even bigger this time!"

In a situation like this, I'm always reluctant to add to the doom and gloom.  But I would be remiss in not pointing out that all of the above is small potatoes, really.  A lot of us, in fact, are concerned at how the current chaos has distracted us from a far, far bigger problem.  We are facing an unprecedented climate catastrophe, not in a hundred years, not in fifty years, but right now. and three papers in the past two weeks have added to what was already a clarion call to action.

Let's start with the deep oceans.  The abyssal region of the Earth's oceans is supposed to be one of the most stable ecosystems on Earth.  Saline, completely pitch dark, crushing pressures, and always at just shy of four degrees Celsius -- the temperature at which water is its densest.  No change, no matter what's happening up above.

But last week a paper in Nature Climate Change looked into the deeps of the ocean, and found something terrifying.  The anthropogenic climate change signature is showing up in a place that is supposed to be about as insulated from human effects as you could imagine.

A team led by oceanographer Yona Silvy of the Université Sorbonne wrote the following:

[U]sing 11 climate models, we define when anthropogenic temperature and salinity changes are expected to emerge from natural variability in the ocean interior along density surfaces.  The models predict that in 2020, 20–55% of the Atlantic, Pacific and Indian basins have an emergent anthropogenic signal; reaching 40–65% in 2050 and 55–80% in 2080.  The well-ventilated Southern Ocean water masses emerge very rapidly, as early as the 1980–1990s, while the Northern Hemisphere water masses emerge in the 2010–2030s.  Our results highlight the importance of maintaining and augmenting an ocean observing system capable of detecting and monitoring persistent anthropogenic changes.

Perhaps this should have been unsurprising, considering that 93% of the anthropogenic heating the Earth is experiencing is being absorbed by bodies of water.  But the idea that this absorption isn't limited to the surface -- that we're actually impacting the deepest parts of the world's oceans -- is seriously scary to anyone who knows anything about the environment and climate models.

Scientists have long been concerned about the tipping point -- the point that climatic catastrophe becomes inevitable no matter what we do.  A second study out of Ohio State University has shown conclusively that we've passed that point with respect to one of the Earth's systems, the melting of the Greenland Ice Sheet.

What the researchers found was that up until about the year 2000, the glaciers in Greenland were pretty well in balance.  The amount of ice loss during the summer was nearly equal to the amount of ice gain from snowfall during the winter.  But around 2000, the situation changed, and since then Greenland has lost a staggering 50 gigatons (50 billion tons) more ice than it gained.

"Glacier retreat has knocked the dynamics of the whole ice sheet into a constant state of loss," said Ian Howat, who co-authored the paper.  "Even if the climate were to stay the same or even get a little colder, the ice sheet would still be losing mass."

[Image licensed under the Creative Commons Christine Zenino from Chicago, US, Greenland Glaciers outside of Ammassalik (5562580093), CC BY 2.0]

The polar bears aren't the only ones who should be concerned.  Greenland is second only to Antarctica in its potential effect on sea level rise.  If the Greenland Ice Sheet melts -- which is has sometimes done during warm periods in Earth's climate -- it would raise the sea levels by six meters.  Everywhere under six meters of elevation would be under water.

So wave goodbye at New Orleans, Antwerp, Charleston, Boston, a good chunk of New York City and Long Island, and most of Florida, Delaware, the Netherlands, and Bangladesh.

If that's not bad enough, a paper in The Cryosphere last week, authored by a team from three universities -- Leeds, Edinburgh, and University College London -- considered the situation worldwide, and found that in the past twenty-three years, the Earth lost 28 trillion tons of ice.

"To put that in context, every centimeter of sea-level rise means about a million people will be displaced from their low-lying homelands," said Andy Shepherd, director of Leeds University's Centre for Polar Observation and Modelling, in an interview with The Guardian.  "In the past researchers have studied individual areas – such as the Antarctic or Greenland – where ice is melting.  But this is the first time anyone has looked at all the ice that is disappearing from the entire planet...  What we have found has stunned us.  There can be little doubt that the vast majority of Earth's ice loss is a direct consequence of climate warming."

It's easy to focus on what's right in front of your face and forget about the big picture.  This would be okay if the big picture wasn't so deeply horrifying.  I hate to be another purveyor of pessimism, but we have got to start taking this seriously.  I'm as upset about the pandemic and the global political chaos as the next guy, but this isn't a time to be distracted away from a much bigger issue -- the long-term habitability of the planet.

Let's keep our eyes on the ball, here.

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This week's Skeptophilia book recommendation of the week is a brilliant retrospective of how we've come to our understanding of one of the fastest-moving scientific fields: genetics.

In Siddhartha Mukherjee's wonderful book The Gene: An Intimate History, we're taken from the first bit of research that suggested how inheritance took place: Gregor Mendel's famous study of pea plants that established a "unit of heredity" (he called them "factors" rather than "genes" or "alleles," but he got the basic idea spot on).  From there, he looks at how our understanding of heredity was refined -- how DNA was identified as the chemical that housed genetic information, to how that information is encoded and translated, to cutting-edge research in gene modification techniques like CRISPR-Cas9.  Along each step, he paints a very human picture of researchers striving to understand, many of them with inadequate tools and resources, finally leading up to today's fine-grained picture of how heredity works.

It's wonderful reading for anyone interested in genetics and the history of science.

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