Rivers change course all of the time for reasons unrelated to climate change. It’s entirely likely that the Amazon was some distance from this site 2,000 years ago.
You're entirely right. But the evidence is not a single drought, it's a staggering combination of many events that show things are changing in a drastic way.
Anyway it's also important to point out that the climate has changed before, but during humanity's existence it never changed this quickly: it looked more like this https://xkcd.com/1732/ which describes changes along thousands of years rather than a century. The derivative of in respect to time is just to steep.
Another thing to consider is that quickly changing environmental conditions is often associated with extinction events. We are in the middle of one such event https://en.wikipedia.org/wiki/Holocene_extinction but maybe one can say it's okay; on a geological scale, such disasters this happens all the time.
The question is, maybe, to ask what will happen to us and the things we care about.
I'm going to generously assume that you're asking a sincere question and not trying some tired political baiting, even though you mentioned climate change out of nowhere.
Yes, rivers are extremely dynamic -- they run dry, flood, and change course over time. Often, those changes are dramatic and oscillatory so the same path may repeatedly run dry or wet over periods of years, decades, centuries, millennia, and longer. This is why we can often predict where droughts and floods are likely to recur, without precise timing of when. None of that has anything to do with climate change.
"Climate change" didn't come in vain: there are many news using small events as a final proof of a new ice / greenhouse / warm / climate change era. So, can the fact of something happening in the past be a proof of something ? And yes, your reply was a good one. Assume "good faith" should be the norm to a open and sincere debate... Thanks!
This is a good opportunity to point out this strategy of climate denial, and why it is not a rational approach to refuting climate change.
Let's suppose that all the other commenters are wrong, that the river has not changed course in the past. The implication, from a probabilistic perspective is that P(evidence|climate change) is the same as P(evidence| natural variation), and your implied assumption is that because your prior belief that no climate change is more likely than climate change, then this works ultimately as evidence in favor that there is no climate change.
The reason this does not yield interesting results, even if all these other assumptions we're making hold, is because the hypothesis of climate change doesn't simply explain this one observation, it explain an enormous range of phenomena.
To explain away all of the observations explained by climate change you end up building a huge list of different hypotheses to explain away each fact. Even if individually these alternate hypothesis do explain each piece of evidence better (which in practice they often don't), and even if your prior for all of these other hypotheses is higher than climate change, because climate change is a single hypothesis that explains many observations, the joint probability of the individual hypothesis quickly becomes much lower than the climate change hypothesis.
In order to effectively argue against climate change you would need a competing singular hypothesis (or small set of very likely hypotheses) that ultimate do a better job explaining all of the observations we have collected.
I don't know if this fallacy has a name, but it sure should since it comes up in a lot of arguments about systemic problems.
Depending on how well digital records are preserved I think future people might run into the opposite problem, so much information that there is absolutely no mystery about what people thought and believed.
Even with all the information at our fingertips, I still don't know what a person dreams of, hopes for, cries about, longs for, and ultimately, who the person really, truly, is, because us humans are all too good at sharing everything, but the truth of our humanity, the things that make us vulnerable, so we invent a shallow shell of a personality over the years to protect ourselves and thus we put out there only that we think is acceptable to put out there all while remaining in solitude with our actual self. I wish it would be different.
We're basically still living in the cultural mileu formed in Rome, though. I would expect to have much more cultural connection to someone in Rome in 0AD than someone in the Amazon in the 14th century.
Look at the letters you just typed. They're an incredibly efficient information transmission technology. By making the minimal energy expenditure of moving your fingers across the keyboard you're able to convey so much of your current emotional state and ideas in your head. While people thousands of year back only had the stone and who knows what other tools to do the same, but at the much larger cost of carving stone, and only with a minimum of effectiveness in conveying their emotional state, which for us, will forever remain unknown.
People generally dont know it, but the facts/debate around the sophistication of populations thousands of years ago, and how those vary across geographies, is extremely political. There is generally an unseen hand that dictates the narrative around the distant human past. You can pull the facts together, but the full picture is almost never presented cohesively to the non academic population.
Like horses in the Americas. There is a narrative that horses were in the Americas, then died off, then were reintroduced by Spanish conquistadors. But, there is sporadic evidence that horses did exist in the Americas the entire time.
I was also skeptical, seems there’s a lot more to this story. Not that they didn’t disappear and reappear, but the spread of them isn’t as straightforward as we thought.
That's basically the same claim. This is saying "the europeans brought them, and they spread around faster than we thought". Which is interesting and fine, but that's a far cry from the above claim of "actually, that ten thousand year period where they appeared to be extinct never happened and they were around the whole time".
Honest question as I have no horse on this race (pun intended) and you picqued my curiosity. How the hell can the pre existence of horses be politicized?
I guess it adds weight to the whole "natives own this land and colonizers didn't bring anything to this land", notably as push back against the other side which is "natives are backwards and this land wasn't all that useful until we brought technology (horses)."
Both caricatures ofc. But then again, they have to be because in the political arena details and facts don't matter at the end of the day as it's all about marketing.
We had a Mayan guide when we were in the Yucatan on vacation. He spent quite a bit of time pointing out proofs (as the native Mayans see them) of horses being around the entire time. He claimed to have a college degree in archaeology, but went on a rant about non-Mayan archealogists and their bias against native Mayans. Basically, he saw the disbelief against horses being around the whole time as racially motivated. Those dumb mayans don't know what they are talking about. I'm trying now to remember the proofs he was showing, but at the time I remember being pretty surprised since it seemed cut and dry.
> I'm trying now to remember the proofs he was showing
I don't want to sound mean, but without any links to anything, any mentions of books, papers, even mentions of archaeological finds in local newspapers... what you're saying is just a story about someone you met who made some outlandish claims.
Yes. My takeaway from that account wasn't that there is necessary a hidden truth, but that some people do believe there is one and such belief correlates with their identity politics.
The fact that the argument appears to be cut and dry is also testament to the fact that it has been rehearsed many times and shared within that identity community
It's pretty dubious because horses themselves -- the kinds of horses we domesticated and ride -- are descendants from a pretty isolated genetic pocket in the Pontic-Caspian steppe, potentially all descended from a single male even.
The kind of horse that could be domesticated and ridden was not widespread, and in fact were really just hunted for meat until maybe 6500 years ago, and actually riding them came even later...
So, I mean, maybe there were equine species in North America, but their relationship to humans I doubt would be anything like what we think of horses like right now. More like a hunted species like bison or deer...
Now, dromedaries I can see. Camels, alpacas, and llamas etc. Long and ancient history with those, and in both hemispheres independently.
There was, in fact, an american horse that died out that we likely hunted (or at least coexisted with). There is zero evidence of domestication of which I'm aware, though.
Camels are crazy and work well in both cold and hot climates. I saw something (I think a PBS documentary) that said they originally weren't adapted to the desert, but the artic of northern Canada or something crazy like that (many many millenia ago).
They might not have interbred- dogs existed in the Americas but left very little genetic mark. The chihuahua is a European breed that was bred to look like a dog that existed in Mexico.
> There is a narrative that horses were in the Americas, then died off
They died off (along with mammoths and lots of other large mammals) around the same time as humans arrived in the Americas and hunted them to extinction.
There are certainly political threads. American westward expansion had to be justified, for example, by claiming cultural superiority over the people who were being displaced.
Westward expansion was much more than individuals taking land. There were military outposts, laws passed, articles written, battles fought, court cases argued, protests, disagreements among Americans, etc.
"Americans justified westward expansion through the ideology of Manifest Destiny. Manifest Destiny was a term coined in the mid-1840s. It claimed that the United States was providentially designed to spread across the continent. Believing their "civilization" to be superior to Native and Mexican peoples, it supposed their lands should rightfully be part of the United States. This led to the brutal subjugation of Native tribes as millions of Americans flooded west in the decades after the Civil War."
>They saw the land was lightly populated and took it.
This framing is passive and hides the history that our own government even admits to[1]. The west wasn't simply lightly populated. There were state-sponsored and well documented extermination campaigns that cleared the land for white settlement.
What makes you say that?
Some studying the California natives put their population at 300,000, some all the way up to 1.5MM and that's after they were hit by waves of infectious disease.
Primarily this is just a direct reply to the person above me. That said, the way we view historical cultures is impacted by politics, and to properly understand the archeological record we need to be able to separate politics from facts. We cannot do this if we don’t recognize the distinction.
Though in the cases of colonial history our access to the records are based in politics. Many texts were destroyed and our connections to the cultures that produced them were destroyed along with them.
Wherever the popular narrative goes, there is also a huge amount of real uncertainty about the sophistication of the people that lived at the prehistoric Amazon.
The forest hides and destroys stuff extremely well.
in Italy there are "the stones of famine".
not that old but interesting anyway.
one reads "if you see me you must be crying".
https://blog.3bee.com/pietre-della-fame-siccita/
sorry... can't find english version.
The article closes by quoting an historian involved: "Having our rivers back (flooded) and keeping the engravings submerged will help preserve them, even more than our work."
Is there a risk to the carvings by being exposed to air rather than the erosive river currents? In colder climates, freezing can erode rocks, but I don't imagine that's relevant here.
Think of those dinosaur fossil teeth that survived buried for hundreds of millions of years, only to get dug up by a fossil hunter, sold to a collector, lives on the collectors mantlepiece for 40 years, then lives in boxes in the collectors sons attic for 60 years, and finally gets trashed (incinerated, destroying it).
Eg: the pictured carvings are on collapsed rock shelves, presumeably these were above normal river level when carved and in a two thousand year period the river has undercut the rock shelf and they've colapsed to below the usual river level.
In fact there are many possible reasons why your apparent smug bad faith poo poo climate change comment isn't well considered.
I'm downvoted, but why? I'm simply making the obvious observation - that the river got this low 2000 years ago, but today the drop is blamed on climate change.
> the pictured carvings are on collapsed rock shelves, presumeably these were above normal river level when carved and in a two thousand year period the river has undercut the rock shelf and they've colapsed to below the usual river level.
You presume something that is not expressed in the article. There's nothing about the river undercutting the rock shelf and causing a collapse - that's an act of imagination on your part.
If you simply take out the political, environmental slant (out of the article, and your mind) and just look at what is stated, the most obvious conclusion is that every so often this river drops lower than usual. And that droughts, floods, etc have always been part of life on earth.
> It's right there in the pictures, layered strata, rock shelf, carvings on rock collapsed off of the shelf.
It isn't.
The article says:
> The rock carvings are not usually visible because they are covered by the waters of the Negro River, whose flow recorded its lowest level in 121 years last week.
There is no mention of "collapse", "strata" or "shelf". Are we looking at the same info?!?
I didn’t downvote you but I assume it’s because you’re saying a drought is evidence of climate change. Regular droughts might be visible effects of climate change but they can happen during a period of general stability too.
I'm not saying that a drought is evidence of climate change - I'm saying the opposite.
The article ties climate change into this, when it says:
> According to experts, the dry season has worsened this year due to El Niño, an irregular climate pattern over the Pacific Ocean that disrupts normal weather, adding to the effect of climate change.
but there is no reason to think climate change has anything to do with this. The article itself also says:
> The rock carvings are not usually visible because they are covered by the waters of the Negro River, whose flow recorded its lowest level in 121 years last week.
ie 121 years ago, the river was recorded as being this low. ie before climate change.
For me this is another 'climate change' article, but is interesting as not all the claims the article makes can all be true.
Climate change does not simply cause more severe weather events but also more frequent severe weather events. This means a "once in a century" event can turn into a yearly occurrence. It's also a cumulative process with cascading effects and emergent properties, so you can't just reduce the factors that contribute to the climate crisis and get back to where we were before the same way you a molten candle won't turn back into its original shape when you remove the heat.
A lot of climate science has been dumbed down to "it's getting warmer" in popular media, which isn't wrong, but people misunderstand this as "winters get less cold and summers get warmer" which isn't necessarily the case in every place.
There's more energy in the system. Imagine an intricate network of tiny machines all working in unison (heck, think of a road network with driverless cars if you want) and then making everything run much faster with no regard for physical constraints and mechanical properties. Eventually there will be collisions and those will have effects on other parts of the network and the more complex the initial system is the harder it becomes to predict what will happen exactly but even if you stop increasing the speed and allow for the system to stabilize, it will be very different from how you started and even if you slow it down back to the original speed, the system will look different. If you imagined this as a road network, humanity and other animals are the pedestrians trying to cross the streets and there are no traffic lights. I hope this metaphor also demonstrates how historical changes effectively just slowed down and sped up the traffic a tiny bit (say, going slightly above or under the speed limit). The implications for the system overall and for the pedestrians within are very different.
However, your answer has 'climate change' baked in. What evidence is there in this article to suggest climate change, rather than an intermittent event that has probably occurred numerous times in the past 2000 years? Why does the article say 'climate change'? Why do you think it? Why was the river low 2000 years ago, in pre-climate change times?
The thing is that there have always been droughts, floods, etc - these were recorded in biblical times. That most people frame 'changing weather' in terms of climate change is a question of psychology and education - but has nothing to do with any evidence anyone can see and verify. We have to simply told to accept the provided 'climate change' explanation.
The weather has always changed - its not running faster now, or at least I don't have any reason to this it is. What is running faster is the level of information being provided on weather.
> What evidence is there in this article to suggest climate change
The article is not about climate change, it's about a drought. It doesn't try to present evidence for climate change.
> The weather has always changed
The plural of weather is not climate. Weather is an emergent effect of the climate. I don't have a collection of references to dump on you to demonstrate climate change because it's the scientific consensus, even within the United States. At this point, if you're scientifically literate enough to be on HN, you're scientifically literate enough to look up scientific explanations for why your intuitions and concerns about climate change maybe not being a thing after all are wrong. I'm not going to spend my finite lifetime trying to argue this with a person on the Internet, especially someone who might be religiously motivated.
85 comments
[ 2.8 ms ] story [ 154 ms ] threadAlso, natural climate change also occurs, the current one is man made.
Anyway it's also important to point out that the climate has changed before, but during humanity's existence it never changed this quickly: it looked more like this https://xkcd.com/1732/ which describes changes along thousands of years rather than a century. The derivative of in respect to time is just to steep.
Another thing to consider is that quickly changing environmental conditions is often associated with extinction events. We are in the middle of one such event https://en.wikipedia.org/wiki/Holocene_extinction but maybe one can say it's okay; on a geological scale, such disasters this happens all the time.
The question is, maybe, to ask what will happen to us and the things we care about.
Yes, rivers are extremely dynamic -- they run dry, flood, and change course over time. Often, those changes are dramatic and oscillatory so the same path may repeatedly run dry or wet over periods of years, decades, centuries, millennia, and longer. This is why we can often predict where droughts and floods are likely to recur, without precise timing of when. None of that has anything to do with climate change.
I hope this answered your question!
"Climate change" didn't come in vain: there are many news using small events as a final proof of a new ice / greenhouse / warm / climate change era. So, can the fact of something happening in the past be a proof of something ? And yes, your reply was a good one. Assume "good faith" should be the norm to a open and sincere debate... Thanks!
https://www.youtube.com/watch?v=UBivwxBgdPQ
Let's suppose that all the other commenters are wrong, that the river has not changed course in the past. The implication, from a probabilistic perspective is that P(evidence|climate change) is the same as P(evidence| natural variation), and your implied assumption is that because your prior belief that no climate change is more likely than climate change, then this works ultimately as evidence in favor that there is no climate change.
The reason this does not yield interesting results, even if all these other assumptions we're making hold, is because the hypothesis of climate change doesn't simply explain this one observation, it explain an enormous range of phenomena.
To explain away all of the observations explained by climate change you end up building a huge list of different hypotheses to explain away each fact. Even if individually these alternate hypothesis do explain each piece of evidence better (which in practice they often don't), and even if your prior for all of these other hypotheses is higher than climate change, because climate change is a single hypothesis that explains many observations, the joint probability of the individual hypothesis quickly becomes much lower than the climate change hypothesis.
In order to effectively argue against climate change you would need a competing singular hypothesis (or small set of very likely hypotheses) that ultimate do a better job explaining all of the observations we have collected.
I don't know if this fallacy has a name, but it sure should since it comes up in a lot of arguments about systemic problems.
It is not from the first people in the area. It is previous people in the area.
Maybe two thousand years in the future someone will read this comment on hacker news and wonder similarly of me
The only thing that's changed is the medium they are written in/on.
https://www.smithsonianmag.com/smart-news/native-americans-s...
Both caricatures ofc. But then again, they have to be because in the political arena details and facts don't matter at the end of the day as it's all about marketing.
I don't want to sound mean, but without any links to anything, any mentions of books, papers, even mentions of archaeological finds in local newspapers... what you're saying is just a story about someone you met who made some outlandish claims.
The fact that the argument appears to be cut and dry is also testament to the fact that it has been rehearsed many times and shared within that identity community
The kind of horse that could be domesticated and ridden was not widespread, and in fact were really just hunted for meat until maybe 6500 years ago, and actually riding them came even later...
So, I mean, maybe there were equine species in North America, but their relationship to humans I doubt would be anything like what we think of horses like right now. More like a hunted species like bison or deer...
Now, dromedaries I can see. Camels, alpacas, and llamas etc. Long and ancient history with those, and in both hemispheres independently.
Edit: more like millions of years
https://en.m.wikipedia.org/wiki/Paracamelus
They died off (along with mammoths and lots of other large mammals) around the same time as humans arrived in the Americas and hunted them to extinction.
https://news.ucsb.edu/2001/011478/humans-hunted-mammals-exti...
Having the Iliad amounts to a cheat code in archaeology.
See this summary linked here and copied in full below: https://homework.study.com/explanation/how-did-americans-jus...
"How did Americans justify westward expansion?"
"Americans justified westward expansion through the ideology of Manifest Destiny. Manifest Destiny was a term coined in the mid-1840s. It claimed that the United States was providentially designed to spread across the continent. Believing their "civilization" to be superior to Native and Mexican peoples, it supposed their lands should rightfully be part of the United States. This led to the brutal subjugation of Native tribes as millions of Americans flooded west in the decades after the Civil War."
This framing is passive and hides the history that our own government even admits to[1]. The west wasn't simply lightly populated. There were state-sponsored and well documented extermination campaigns that cleared the land for white settlement.
1. https://www.nps.gov/articles/000/what-happened-to-the-bison....
What makes you say that? Some studying the California natives put their population at 300,000, some all the way up to 1.5MM and that's after they were hit by waves of infectious disease.
The forest hides and destroys stuff extremely well.
They're all over central Europe.
Is there a risk to the carvings by being exposed to air rather than the erosive river currents? In colder climates, freezing can erode rocks, but I don't imagine that's relevant here.
Think of those dinosaur fossil teeth that survived buried for hundreds of millions of years, only to get dug up by a fossil hunter, sold to a collector, lives on the collectors mantlepiece for 40 years, then lives in boxes in the collectors sons attic for 60 years, and finally gets trashed (incinerated, destroying it).
Eg: the pictured carvings are on collapsed rock shelves, presumeably these were above normal river level when carved and in a two thousand year period the river has undercut the rock shelf and they've colapsed to below the usual river level.
In fact there are many possible reasons why your apparent smug bad faith poo poo climate change comment isn't well considered.
> the pictured carvings are on collapsed rock shelves, presumeably these were above normal river level when carved and in a two thousand year period the river has undercut the rock shelf and they've colapsed to below the usual river level.
You presume something that is not expressed in the article. There's nothing about the river undercutting the rock shelf and causing a collapse - that's an act of imagination on your part.
If you simply take out the political, environmental slant (out of the article, and your mind) and just look at what is stated, the most obvious conclusion is that every so often this river drops lower than usual. And that droughts, floods, etc have always been part of life on earth.
No idea, I was also downvoted by someone, it's not something I fuss about; you'd have to ask the downvoters.
> You presume something that is not expressed in the article.
It's right there in the pictures, layered strata, rock shelf, carvings on rock collapsed off of the shelf.
It's a pretty basic geological observation.
> I'm simply making the obvious observation - that the river got this low 2000 years ago,
That's a shallow conclusion, geologically speaking .. a leap of "can't think of anything else".
There are many possible reasons strata | water relationships might alter over the course of two thousand years. I've fleshed out one.
> take out the political, environmental slant (out of the article, and your mind)
There you go with the poor reasoning and shoddy conclusions based on projected assumption again.
My background is geophysics and my two comments are related to geology and timescales.
It isn't.
The article says:
> The rock carvings are not usually visible because they are covered by the waters of the Negro River, whose flow recorded its lowest level in 121 years last week.
There is no mention of "collapse", "strata" or "shelf". Are we looking at the same info?!?
The article ties climate change into this, when it says:
> According to experts, the dry season has worsened this year due to El Niño, an irregular climate pattern over the Pacific Ocean that disrupts normal weather, adding to the effect of climate change.
but there is no reason to think climate change has anything to do with this. The article itself also says:
> The rock carvings are not usually visible because they are covered by the waters of the Negro River, whose flow recorded its lowest level in 121 years last week.
ie 121 years ago, the river was recorded as being this low. ie before climate change.
For me this is another 'climate change' article, but is interesting as not all the claims the article makes can all be true.
A lot of climate science has been dumbed down to "it's getting warmer" in popular media, which isn't wrong, but people misunderstand this as "winters get less cold and summers get warmer" which isn't necessarily the case in every place.
There's more energy in the system. Imagine an intricate network of tiny machines all working in unison (heck, think of a road network with driverless cars if you want) and then making everything run much faster with no regard for physical constraints and mechanical properties. Eventually there will be collisions and those will have effects on other parts of the network and the more complex the initial system is the harder it becomes to predict what will happen exactly but even if you stop increasing the speed and allow for the system to stabilize, it will be very different from how you started and even if you slow it down back to the original speed, the system will look different. If you imagined this as a road network, humanity and other animals are the pedestrians trying to cross the streets and there are no traffic lights. I hope this metaphor also demonstrates how historical changes effectively just slowed down and sped up the traffic a tiny bit (say, going slightly above or under the speed limit). The implications for the system overall and for the pedestrians within are very different.
However, your answer has 'climate change' baked in. What evidence is there in this article to suggest climate change, rather than an intermittent event that has probably occurred numerous times in the past 2000 years? Why does the article say 'climate change'? Why do you think it? Why was the river low 2000 years ago, in pre-climate change times?
The thing is that there have always been droughts, floods, etc - these were recorded in biblical times. That most people frame 'changing weather' in terms of climate change is a question of psychology and education - but has nothing to do with any evidence anyone can see and verify. We have to simply told to accept the provided 'climate change' explanation.
The weather has always changed - its not running faster now, or at least I don't have any reason to this it is. What is running faster is the level of information being provided on weather.
The article is not about climate change, it's about a drought. It doesn't try to present evidence for climate change.
> The weather has always changed
The plural of weather is not climate. Weather is an emergent effect of the climate. I don't have a collection of references to dump on you to demonstrate climate change because it's the scientific consensus, even within the United States. At this point, if you're scientifically literate enough to be on HN, you're scientifically literate enough to look up scientific explanations for why your intuitions and concerns about climate change maybe not being a thing after all are wrong. I'm not going to spend my finite lifetime trying to argue this with a person on the Internet, especially someone who might be religiously motivated.