We noted in a post last month the extraordinary market in the 19th century U.S. for subscription books (a direct-sales approach to publishing with a long history); even after subscriptions subsided, their infrastructure– sales teams that contained an appreciable number of women– was used to sell books in locations too remote for bookstores. Livia Gershon reviews the risks and rewards of life on the road as a traveling bookseller…
The booksellers visited homes and businesses with sample books, took orders, and then later delivered the books and collected payment. Braun writes that popular volumes included Bibles, farming and health manuals, biographies, and fiction. Ulysses S. Grant’s memoirs and the works of Mark Twain were popular choices. Many books published using this “subscription” model sold hundreds of thousands of copies.
While the vast majority of book peddlers were men, some publishers recruited women with the idea that they would be well suited to sell books on health and hygiene to female readers, and also that customers would find them sympathetic.
In an 1868 account of her work selling books across northern Illinois and Indiana, Annie Nelles Dumond described taking up the work out of necessity. She wrote that, seeking to escape a difficult childhood, she married young to a man who turned out to already have a wife and children. A second husband abandoned her. So Dumond sought ways to support herself.
When she began selling books, she wore a mourning bonnet. She acknowledged that this was deceptive but wrote that it was “almost necessary to my self-preservation that my past should not be known.”
Dumond described pride in her work’s “dissemination of light and knowledge among the masses.” By contrast, in an 1874 book on her own work as a bookseller, J. W. Likins of central California wrote that, despite knowing it was “honorable and legitimate” employment, “it seemed to me very much like begging.”
Likins, who took the job to support her family after her husband became too ill to work, wrote that some potential customers seemed curious or pitying. But a few men were angry to see a woman out on her own, demanding that she go home to take care of her family or incorrectly assuming that she was a suffragist.
More disturbingly, in a third autobiographical account Braun considers, published in 1881, a northern California peddler named Harriet Wasson Styer described a man telling her that, if she were his sister, he would murder her rather than allow her to canvass.
But much of Styer’s account suggested a fascinating experience. She recounted traveling to lumber camps and mining towns, admiring the wild landscapes, and coping with bed bugs and dirty stagecoaches.
Braun notes that all three peddlers were well aware that they were doing something many people believed was improper for a lady, but they took on the work out of a combination of necessity and a chance for adventure…
As we get a foot in the door, we might send grateful birthday greetings to Herman Melville; he was born on this date in 1819. A writer, he is best known for Moby-Dick (1851), Typee (1846), and his posthumously published (1924) novella Billy Budd, Sailor. The efforts of the booksellers described above notwithstanding, Melville was not well known to the public at the time of his death in 1891. But the centennial of his birth was the starting point of a Melville revival; Moby-Dick is now, of course, considered one of the Great American Novels.
Further to the post of Septmeber 15: on trying to understand what might lie on the other side of a transformation driven by AI (and related technologies). Microsoft’s Deputy CTO, Sam Schillace, suggests that organizations are about to change completely…
… Here’s a nerdy TL;DR if you want it: I think AI will enable a switch from what is essentially circuit switching today, in all kinds of organizations, to something that will look and feel a lot more like packet switching. This will happen partially because it can now (AI is to this problem what fast processors were to distributed networking protocols), and because networks are almost always more powerful, flexible, and scalable. This idea is going to feel super uncomfortable and be rejected by business leaders, employers and academics in much the same way that network engineers rejected the idea of packet-switched networks…
… In 1965, making a long-distance phone call in America was a feat of engineering coordination. A call from New York to Los Angeles required a dedicated copper path, physically reserved, for the duration of the conversation, and AT&T had to employ armies of switching engineers to manage this. The Bell System was one of the great technical achievements of the twentieth century, and the people who built it were not fools. They worked ferociously for what they were optimizing for: guaranteed, high-quality, reliable connections between two points.
It seemed fine – expensive, but that’s what everyone was used to. If you are my age, you remember when long-distance was even a thing, and those calls cost more and were precious. I still get a tiny bit nervous talking to my parents 3000 miles away in Michigan, that was so deeply ingrained. Part of me still can’t believe that phone calls all cost the same.
Then a small group of researchers, largely funded by ARPA, mostly working in universities, proposed something that sounded to the Bell engineers like a joke. Instead of reserving a dedicated path, you would break messages into small pieces, label each piece with a destination, and release them into the network to find their own way. Different pieces of the same message might travel completely different routes. They might arrive out of order. There was no guarantee that any particular piece would arrive at all. A phone call, under this scheme, would be like mailing a letter by tearing it into a hundred pieces and dropping each one in a different mailbox, hoping they’d all show up. (Kind of like training a giant AI model on lots of small fragments of language (tokens) and hoping that somehow intelligence would emerge from putting them back together randomly – which largely worked).
The Bell engineers had a name for this general idea: chaos. They had a specific critique too, which was that you couldn’t make any guarantees about quality of service. Voice needs low, consistent latency: you can’t have some syllables arriving seconds after others. And of course, data needs reliability: a corrupted file is useless. The engineers were right about all of this. Packet switching, in its early forms, was genuinely worse at the things circuit switching was designed to do.
It also, within a few decades, made the Bell System irrelevant. The internet didn’t improve on the telephone network; it made the telephone network a minor application running on top of something much larger. Today your phone calls travel as packets (which is why they all cost the same – there’s no such thing as a “long circuit” now), just like everything else. The Bell engineers optimized for the wrong thing. I love that this also has a flavor of “worse is better”. The Bell engineers were optimizing for “correct, complete, but complex and rigid” and the internet is more “simple and recoverable beats correct and complex”.
What actually happened was a philosophical shift about where intelligence should live. Circuit switching is a centralized control philosophy. Someone, somewhere, reserves the path before any message travels it. The network takes responsibility for delivery. The endpoints are dumb; they just send and receive. All the complexity, all the guarantee-making, lives in the infrastructure itself. This works, and it scales up to a point, and then it hits a wall, because the central system has to know everything about every connection, and that knowledge becomes impossible to manage as the network grows. (Sound familiar? This is how we build companies these days. We’ll come back to that idea)
Packet switching inverts this entirely. The network is dumb and the endpoints are smart. A router doesn’t understand the content of the packets it handles – it reads a destination address and forwards the packet one hop closer. The intelligence about what the message means, whether it arrived correctly, what to do if it didn’t – all of that lives at the edges, in the devices doing the communicating. The protocol defines what the endpoints must do. The network just moves bits.
You have seen this argument before, in a different domain. Central planning versus markets is the same disagreement. The Soviet planning apparatus tried to do for an economy what circuit switching does for a telephone network: reserve resources, guarantee outcomes, manage the whole system from the center. It failed not because the planners were stupid but because the information required to run a complex system centrally exceeds what any center can hold (it also failed because many of them were corrupt, and centralized systems are vulnerable to this, since there’s no way to build in mechanisms to correct, outcompete or otherwise reverse that corruption).
Prices, in a market, are packets. They carry information about supply and demand from the edges without anyone at the center having to understand or coordinate it. Markets are chaotic, wasteful, frequently unfair, and they consistently outperform central planning at scale for the same reason the internet outperformed the Bell System. The network always wins, eventually, because the network is where the information actually lives.
Let’s think about companies now. Companies love to do re-orgs. Or at least, they have to do them. They’re a lot of work, just like it was a lot of work to organize and change the old Bell network, and for the same reasons. Companies have to deal with the pain of organizational overhead, because to a large extent, they try to do central planning – circuit switching.
A manager, in an org chart, is a leased line. From an organizational perspective, they’re like a circuit between strategy and execution, reserved whether or not signal is flowing. The org chart is the circuit map. It tells you the paths that exist, which means it also tells you the paths that don’t. If you need to get information or work from point A to point B and there’s no line between them on the chart, you have a problem – you need to go up to a common node and back down, or you need to get someone to lay a new line. When a company needs to change how it behaves, it rewires the circuit map, which we call a reorg.
Why do we do this? This is not because companies are stupid or because the people running them lack imagination (hopefully). It’s because circuit-switched organizations are the only kind that could be managed without the infrastructure that packet-switched organizations require (which isn’t unlike what happened with the internet – we needed cheap processors to be able to build routers that could handle packets fast enough. Before we had that, we had no choice but to set up dedicated circuits).
If you can’t do the things an organization needs – observing and judging work, finding capabilities, holding people accountable – without the overhead of a fixed org chart, well, you just have to have it.
The cost of this solution is enormous and mostly invisible because it’s so normalized…
[Schillace expands on this idea…]
… When packet switching was proposed, the experts who objected most loudly were the most qualified people in the room. They were “right” in an engineering sense, but wrong in the systems sense. And they did what most people do, asking a “why not” question (against the old design and constraints) instead of a “what if” one: what if the new processors could enable a new network design?
Most people looking at AI are making the same mistake, and I predict we will see a lot of this from the orthodox “business advisor” community. I hear this from engineers and leaders already, and it sounds just like the Bell folks: You can’t guarantee accountability in a decentralized system. You can’t audit a network that routes around hierarchy. Regulators will never accept this. Sophisticated investors will raise concerns about governance.
All of these objections will be correct in the short term and beside the point in the long term. They are right from some kind of local engineering perspective but wrong from an emergent systems perspective. The question is not whether packet-switched organizations perform better on the metrics that circuit-switched organizations were built for. They won’t, at least at first, just like packet-switched networks didn’t at first. The question is whether the new architecture unlocks things the old one couldn’t do at all. And I think it will – I think we will get levels of scale, creativity and responsiveness by using these new tools to push intelligence to the edge of all kinds of organizations – not just businesses but political, social, educational and creative ones…
…There is a useful heuristic here, which is that disruptive ideas tend to produce a room that’s roughly split in half. Usually something like half the people think the idea is obviously correct (the folks asking “what if”), and half think it’s obviously wrong (the “why not” crowd). I’ve written about this kind of bifurcation before – this is the sign of something that is genuinely disruptive, and the split is between people who are rejecting it because it feels threatening, and people who have internalized the new world view and are beginning to extrapolate it…
[Schillace considers earlier, unsuccessful attempts at “packet-switched organizations,” concluding that “AI is [the] missing piece – cheap enough intelligence to put “everywhere” and enable a bunch of these ideas for real. It’s the equivalent of those cheap processors [that enabled packet switching] finally showing up, except it’s a much more complete stack arriving all at once” and that the next few years will consist in discovering the new protocols that will allow “packet-switched organizations” to succeed…]
… The Bell engineers who resisted packet switching were not, in the end, wrong about what they said. Voice quality did suffer in early VoIP, packets did get dropped a lot, and for a while, quality was worse. But they were wrong about what would matter in ten years, and catastrophically wrong about what would be possible in thirty.
Email was not a better telegram, the web was not a better encyclopedia, and streaming was not a better cable network. Each of these looks, in retrospect, like an obvious evolution, but none of them were conceivable from inside the circuit-switched world (I remember the freak out about how video was going to break even the highly scalable new internet. It wasn’t even thinkable in the circuit switched world). They required the new infrastructure before anyone could imagine what to build on it.
The organizational equivalent is similarly hard to see in advance. It is likely that packet-switched, AI-native organizations will not just do existing organizational things more efficiently, but that they will do things that are not currently possible. There might be organizations that form around specific problems and dissolve when the problem is solved, rather than persisting as structures in search of purpose, or expertise that routes to where it is needed rather than being allocated by headcount. We might have large groups with a degree of strategic flexibility and sophistication that have never existed together – we might get political or creative movements in radically different shapes because of that. We are definitely going to see an evolution in the creation, management and use of institutional memory. Training will probably look very different, as will job descriptions.
And almost certainly: we will get things we cannot name yet. Nobody in 1975 could have described Google, or Facebook, or VOIP, or even Google Docs.
The phone company’s engineers built something extraordinary. The Bell System was a genuine engineering achievement, and the people who designed it were some of the best technical minds of their era. They lost anyway. Networks are more robust, once the infrastructure to support them exists, and the right protocols to create and maintain them are adopted.
My bet is that the organizations of the future, the ones that compete and thrive, will make use of AI to build networks the same way the internet made use of those cheap processors and new protocols to build huge scale and new capabilities.
This will feel controversial, and might even be worse at first, but networks always win. The age of centrally planned organizations is coming to an end…
… With every new technology, we start by using it for the work we already have, and we just do that more and faster. But then, over time, you make entirely new things. We will use AI to automate broad classes of stuff inside existing workflows and existing companies (although, as I’ve outlined above, that will be enormously more trouble and work than just giving everybody a model). But with every previous platform shift, the stuff that actually mattered was the stuff that wasn’t even possible before and that no-one even imagined…
* Bob Dylan, “Ballad of a Thin Man” (from Highway 61 Revisited, 1965)
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As we try to peer over the horizon, we might send carefully-calculated birthday greetings to a man whose work has helped propel the advances we’re pondering: James Hardy Wilkinson; he was born on this date in 1919. A mathematician, he is best known for his pioneering work in numerical analysis and numerical linear algebra, especially in the context of high-speed digital computing. In 1970 he won the ACMTuring Award.
Sumana Roy, with an arboreal meditation on time and rebellion against the straight line…
Have you seen the shape of a solitary tree on a mountaintop? There is no arrogance—it is not the monarch of all it surveys; its shape is that of survival, of fighting annihilation. If a morning hints at the DNA of the approaching day, might the shapes of young plants give us an intimation of what they will look like in advanced age? It must be this sense of amorphousness in the tree branches, going and growing, that makes me think of the shape of smoke, rising dark from the mouths of moving machines, marking the air as they travel, annotating their journey. . . . Are there knowledge systems in these shapes that might inform our understanding of art, creativity, knowledge systems, of time and history, of life and the living?
From the foothills I stare at the mountains and watch the evening grow; daylight suddenly ages, then dies. In the moment’s susurration, one could forget that the sun will return in the morning. Lights wink in the houses on the hills, spare sets of eyes for the dark—or like flowers budding, then blossoming. But that analogy doesn’t quite hold, because for those lights to be flowers, the houses need to be treelike. And our houses are not shaped like trees.
It is difficult to compare the shapes of trees with almost anything else. A flag flutters in the wind, and I can sense the longing of my mind to compare the character of that movement with those of leaves annotating the wind. But the flag mast is not a tree branch and no leaf moves like a flag, not even the banana leaf, whose behavior I’ve often mistaken for a Buddhist prayer flag. Sometimes when I watch leaves being tickled by the wind, I look at the tree nervously. It reminds me of a parent throwing their child up to the sky and catching her again, carrying her in so many ways, with risk as much as assurance. In this is a knowledge system of trust, how the branches hold the leaves and allow them to move without fear.
And what can a leaf’s shape tell us about its home? A palm’s leaf is like paper torn into strips that still manages to hold itself up. Where does such a shape come from? Does it offer protection from the wind, preempting what a strong sea breeze will eventually do? I have seen what such wind can do to billboards—puncturing them, tearing the faces of models and actors with unrelenting force, with a kind of strength that one can imagine only of bombs. There’s also the opposite: the shining solidity of a glossy jackfruit leaf confident even against the bullets of tropical rain. And their branches—hardy, patriarchal and solid, fortresslike, for they must hold the many fruits that cling like baby monkeys to their mothers. When I see the branches of different species, it is as if I can see their birth certificates. It is as if the shapes of the branches are a consequence of a negotiation, not only between the tree and the wind, but also between the tree second-guessing the behavior of the wind generally as well as the particularity of the wind in its home. What I see before me, then, is the shape of the creative process—the arrival of an idea in a leaf’s unfurling, followed by the acknowledgement of life’s exigencies and pauses in the influences of wind, water, and light. When it comes to branches, then, nothing beyond the search for sunlight is modular—everything is ad hoc, growth is provisional, spontaneity is not a choice but a compulsion. A tree’s diet is simple—water and light, but often inconsistent, and in its branches we see the shape of improvisation, of how artists and scientists adapt as circumstances change.
I am aware that I am seeking something beyond the botanical when I graze upon these branches. Is there a hidden history about form, about genre or about genealogy that I crave? In trees, I find a unit of time that is different from other kinds of living time—time is visible in the girth and growth of their branches, a history of ingestion manifest in the visual biography of its form. The difference in the ideas of time perhaps comes from our conditioning in stillness and mobility and, of course, from the directions of movement. Trees move, but usually—by which I mean visibly—northward; humans, mammals, and animals in our vicinity travel east or westward. In this, too, is the variety of our experiences of time.
I think of tree branches that, in search of light, have moved in the same direction. I will never know whether they wanted to meet—their crowns are, of course, shy, as the name of the phenomenon reminds us. The arrangement of branches might, for a moment, remind us of railway tracks, but there is no intimation in the latter of the death, the knowledge system we are all moving toward. Adulthood is the realization that time does not die with our death, and though one might be penniless and without possessions, one will always leave behind something: time, memories, an inheritance, for strangers to use. The absence of humans to the eye when looking out at the landscape from a train also does something—when humans do appear, they feel like numerals on a large clock, something upon which the eye may rest upon, but only for a moment, no longer. I don’t know of any tree whose branches are arranged around the trunk like the numbers on a dial. Sometimes I see a flight of stairs. They seem to disrupt the flow of time. I gradually begin to see that the uneven branches of trees, of varying lengths and thickness, do the same. Sometimes black smoke billows out of chimneys of brick kilns. In its sturdy curving, it has the arrogance of a statue—it stays in that position, as if it were holding its breath underwater, refusing to move. It looks ominous at first and comical in the end, like ambition does. How is its waywardness different from those of tree branches? Does it move like the branches of a tree, seeking something that it needs, or is it without hunger? The smoke will dissipate, of course, but the branches remain. But do they behave similarly in occupying the sky? The heads of the tea shrubs in the tea estates, growing beside the railway track—the youngest leaves picked by human hands keep the bushes flat as does the annual trimming in winter. In the difference of height and growth between the well-endowed shade trees and the tea plants is a quantifiable measure of a history of oppression.
Think of how branches get thinner as they move away from the earth. In this, they are not unlike air itself, in that the form of the trees becomes mirror images of roots. What does that do to our consciousness, for there is no resemblance between our feet and our head? Thin trees—young, planted recently—are straighter than older trees, in that they are like humans themselves, erect when younger, then slouching with age. Is Time erect like that? When does Time grow like grass? See how the branches touch the sky—poking, punctuating, even puncturing it. In these shapes also is some kind of constant self-revision, like a river that is constantly changing its course. Or at least that is what it seems like to an outsider species such as myself. In every knot, in every hole, in every bend, in every stop, in every pause, in every crest, in every depression, in every curl is a history of resistance offered by its surroundings. Form, then, is the result of a negotiation with the world, both of affiliation and disaffiliation, of support as much of antagonism. A history is revealed to us without any middleman or interpretation—a history that is so direct it surprises us, for we are not used to it. The shape of these branches—of history itself—is a rebellion against the straight line, against its autocracy. It reminds me that nothing can be reversed, that “undo” is a capitalist scam, that W. S. Merwin could not “unchop” a tree by assembling its branches together again…
As Gary Snyder reminds us, “Nature is not a place to visit, it is home.”
* Herman Hesse
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As we learn from our elders, we might send fruitful birthday greetings to Nehemiah Grew; he was born on this date in 1641. A plant anatomist and physiologist, he is known as the “Father of Plant Anatomy.” Grew trained, then practiced, as a physician; but his passion was plants. In 1665, he was elected a Fellow of the Royal Society on the strength of his paper The Anatomy of Vegetables begun. In 1682, he published what is considered his most important work, Anatomy of Plants…
It was divided into four books, Anatomy of Vegetables begun, Anatomy of Roots, Anatomy of Trunks, and Anatomy of Leaves, Flowers, Fruits and Seeds, and was illustrated with eighty-two plates, while appended to it were seven papers mostly of a chemical character.The Anatomy is especially notable for its descriptions of plant structure. He described nearly all the key differences of morphology of stem [or trunk] and root, showed that the flowers of the Asteraceae are built of multiple units, and correctly hypothesized that stamens are male organs. Anatomy of Plants also contains the first known microscopic description of pollen. – source
When records began in 1963 there were only 153 centenarians in Japan – now there are 107,677…
The number of people aged 100 or more in Japan has exceeded 100,000 for the first time, according to the health ministry.
Figures show Japan is now home to 107,677 centenarians, the highest number in the world, of whom 88% are women. The oldest woman is Kishimoto Fuyo, a 114-year-old from Kyoto City and the oldest man is Kato Hikaru, a 112-year-old from Kumamoto.
Health Minister Kenichiro Ueno said he was “delighted that so many people are living long, healthy and active lives”, citing progress in medicine and technology.
But Kenichiro also warned of the challenge the country faces in maintaining a sustainable social security system.
Experts put the long lives of the Japanese down to several factors, including a healthy diet and an active lifestyle.
The island nation’s cuisine predominantly consists of fish, vegetables, and rice – and less saturated fat than many Western diets.
Older people also regularly walk, use public transport, cycle and stretch.
… Residents aged 65 and older currently make up around 30% of the population and are expected to make up nearly 40% by 2070.
Japanese authorities have called the trend an “existential crisis” with Prime Minister Sanae Takichi describing the decline as a “quiet emergency”.
In 2025 Japan’s total population decreased in all 47 prefectures but two, and the rate of decline is accelerating.
The government’s many programmes and subsidies to encourage young people to have more children do not appear to be boosting birth rates.
Experts say the reasons are complex, ranging from lower marriage rates and more women joining the workforce to the increased costs of raising children.
While immigration has risen in previous years, foreigners only make up around 3% of the population and opposition to accepting more has grown…
As we age, we might recall that it was on this date in 1964 that “Time Is on My Side,” written by Jerry Ragovoy and originally recorded by jazz trombonist Kai Winding and his Orchestra in 1963, was released as a single by The Rolling Stones in the US. (The song had also been released as a B-side by R&B singer Irma Thomas a month before the Stones’ version was issued.) The loosely arranged recording with an organ intro was included on the band’s American LP, 12 X 5, and a more tightly arranged version with a guitar intro was recorded in Chicago later that year and included on their second UK album, The Rolling Stones No. 2.
Water levels are running dangerously low in reservoirs across the U.S. Southwest. Declining flows in the Gila River have pushed levels to below 1 percent of capacity in Arizona’s San Carlos Reservoir
The Western U.S. is grappling with an extended drought. Nikk Ogasa explores the possibility that this continued dryness (and the fires and other hazards associated with it) could be our new climate change induced reality…
Kearny, Ariz., is a town on the brink. Located at the foot of the Dripping Spring Mountains in eastern Arizona, this small community of 2,000 people sources its water from the Gila River, a verdant waterway that snakes by the southern edge of town.
But in March, the snowpack feeding the river had dropped to precipitous levels: It was just 1 percent of its historic norm for that time of year. The Gila River water commissioner slashed Kearny’s allotment of river water by some 85 percent. And in April, town officials announced that “Zero Day” was approaching, at which point the taps would run dry.
“We need rain,” says Norm Warren, a lifelong Kearny resident. He owns the only large grocery store within a 45-minute drive of the town. Without tap water for refrigerator cooling systems, Warren says he won’t be able to store perishable products like meats and fresh produce.
Kearny’s dilemma foreshadows a crisis building across the American Southwest. Since 2000, the region — which includes Arizona, New Mexico, California, Utah, Colorado and parts of northern Mexico — has endured a historic “megadrought,” or a period of severe dryness that persists for decades. Scientists say it’s the driest this region has been in 1,200 years.
“We’re 27 years into it, and it shows no signs of letting up,” says Brad Udall, a water and climate researcher at Colorado State University in Fort Collins.
Scientists point to two factors causing the drought — rising temperatures and declining precipitation. Heat from human-caused climate change creates a thirsty atmosphere that is more effective at drying out the landscape, says Kevin Anchukaitis, a dendrochronologist who runs the University of Arizona Laboratory for Tree-Ring Research in Tucson. As for the lack of rain, many researchers wonder if it is simply a stroke of bad luck.
But a controversial study published in Nature in 2025 suggests something far more ominous: Humankind has disrupted a naturally occurring climate cycle in the Pacific Ocean that historically ushered episodes of wet weather into the Southwest. If that’s true, Udall says, things are not looking good for places like Kearny. Other researchers worry that the megadrought may be locked in place for the foreseeable future…
[Ogasa unpacks both the more traiditional analysis and the new hypothesis– that human behavior has disrupted the Pacific Decadal Oscillation, or PDO, an alternating climate pattern in which areas of warmer and cooler than normal surface waters switch their positions on a timescale of many decades…]
… “The conventional wisdom suggested that the PDO could shift any given year, and we [wouldn’t] have to worry about drought [after that],” says climate scientist Jeremy Klavans of the University of Miami.
But he and colleagues weren’t so sure. They dug into that assumption, analyzing more than 500 simulations of the PDO from a dozen major climate models. They examined how the PDO shifted — and stabilized — in the presence of outside forces such as volcanic eruptions, solar variation and levels of greenhouse gases and aerosols.
Their finding: Greenhouse gas and aerosol emissions had effectively hijacked the behavior of the PDO over the last 50 years by altering atmospheric temperatures, the team reported in 2025 in Nature.
Ballooning concentrations of industrial aerosols — which can have an atmospheric cooling effect — probably pushed the PDO to increasingly favor its warm phase starting in the 1950s, the researchers say. But in the 1980s, clean air legislation decreased aerosol emissions even as greenhouse gas levels continued to rise and warm the atmosphere. That combination drove the PDO toward its cool phase, making drought conditions more likely in the Southwest. Instead of being a rare event, drought “becomes kind of commonplace,” Klavans says….
… the current climate models may actually be underestimating the potential duration of the ongoing megadrought, based on those findings, says study coauthor Victoria Todd, a climate scientist at the National Center for Atmospheric Research in Boulder, Colo.
That could be bad news for the American Southwest, Udall says. Even if people stopped emitting greenhouse gases today, planet-warming carbon dioxide will continue to accumulate in the atmosphere, locking the PDO and megadrought into place, potentially for decades. If the emerging science is right, then the Southwest is going to keep getting drier and drier, Udall says. “No question about it.”
Warm Phase (1977-1998): During the PDO’s warm phase, the Pacific jet stream (red arrow) moves south over North America, drawing wet weather patterns into the Southwest.
Cool phase (1999–now): When the PDO switches to its cool phase, the Pacific jet stream (blue arrow) moves north, diverting wet weather patterns out of the Southwest and making drought more likely.
The hypothesis that human emissions have disrupted the PDO could be put to the test this year. That’s because scientists are predicting a historically strong El Niño, a Pacific climate pattern characterized by months of warmer than normal sea surface temperatures in the eastern equatorial Pacific. El Niños often bring wet conditions to the Southwest — and they have been known to force the PDO into a different phase. For example, the 1976–1977 El Niño helped push the PDO into a warm phase for nearly a quarter of a century.
But a powerful El Niño in 2015 wasn’t able to force the switch for more than a few years. That suggests the PDO may be slowly changing, Klavans says. “Something’s different here.”
Even if the current El Niño is strong enough to force the PDO into a warm phase, no one should expect the megadrought to go away any time soon, Seager says. “We’re talking about something that’s been going on for a few decades now. Even one very wet winter is not going to be enough to restore Colorado River reservoirs to where they would preferably be.”…
… Even in the best-case scenarios, the Southwest never returns to the wet years of the 1980s and ’90s, when lakes Powell and Mead reached maximum capacity numerous times, the researchers reported in 2023 in npj Climate and Atmospheric Science. The findings instead suggest that, regardless of what the PDO does, the region will face a far drier climate than it did in its recent past. In other words, even if the megadrought were to end, the Southwest faces an uncertain future when it comes to water, according to the study.
Communities need to prepare for the future by improving their water conservation efforts and infrastructure, Anchukaitis says. Those practices will grow only more crucial as the Southwest’s population continues to balloon: Utah, Texas, Nevada, Colorado and Arizona are among the 10 fastest growing states by population this decade, according to a 2024 report by the University of Virginia’s Weldon Cooper Center for Public Service.
Even if wet weather returns, Anchukaitis says, the cities of the Southwest shouldn’t fall into complacency. “[More rain] doesn’t mean that … megadroughts aren’t going to come back,” he says. “Maybe it buys us some time to ease systems into a new way of thinking.”…
As we pray for rain, we might recall that it was on this date in 2006 that NASA recorded th largest ozone hole in the atmosphere to date. From September 21-30, the average area was 10.6 million square miles, as measured by the Ozone Monitoring Instrument on NASA’s Aura satellite. At the worst point, a record low of 1.2 Dobson Units compared to a 125 DU non-hole reading. For the past several decades, each year during the Southern Hemisphere Spring (Northern Hemisphere Autumn) chemical reactions due to chlorine and bromine man-made compounds in the atmosphere cause the destruction of ozone in the stratosphere over the southern polar region… all contributing to the phenomenon discussed above.
False-color view of total ozone over the Antarctic pole. The purple and blue colors are where there is the least ozone, and the yellows and reds are where there is more ozone. (source)
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