One thing we always see when a mass extinction happens is that mega fauna goes first. Large animals can't hide, unlike rat sized ones. Currently so much of the mega fauna outside of Africa has disappeared that we don't even think most continents had any: https://en.wikipedia.org/wiki/Megafauna#Megafaunal_mass_exti...
That would suggest we're 10,000 years into one, rather than being at the early stages of it.
When humans killed off most of the megafauna, it caused cascading extincations. Dire wolves went extinct with nothing to eat. The Osage orange tree nearly went extinct (down to one very small area); it's believed that were spread by Giant Ground Sloth droppings. Tons of dependent plants and animals likely vanished from our "natural" landscape without ever having been recorded.
what megafauna did humans kill off, which you're referring to?
there are rumblings that the ~10k year ago megafauna die off was far too rapid to have been done by relatively unsophisticated humans and is likely to have been caused by a comet fragment impact or similar.
Unsophisticated humans? We haven’t changed much in the last 50,000 years, from what I remember from Sapiens by Yuval Noah Harari. My feeling is that our collective ancestors were creative, intellectual, observant, and all the other positive descriptions we might aspire to, along with being brutal killers fighting to survive. In the span of a couple hundred years we’ve engineered global climate change—-that’s impressive and disheartening, and adopting more of the leave-less-trace existence of our ancestors might be prudent.
> We haven’t changed much in the last 50,000 years
Genetically, not too much. In terms of population density and technology, we absolutely have changed, and both are relevant to our ability to clear a continent of dozens of species of animals at a rapid rate.
technologically unsophisticated. no guns. hard (or impossible) for them to have wiped out a continent of megafauna in the timespans that had previously been suggested.
Humans being the cause is speculation, not fact. It's worth looking into the alternative theories and making your own judgment based on available evidence.
The alternative is that all mega fauna survived a dozen ice ages over the last 5 million years, only for all of them to go extinct when fully modern humans finally invent agriculture by sheer coincidence.
Why is Africa, the place where humans have been the longest, teeming with megafauna relative to the rest of the world? Why did megafauna die out in regions where there was little to no human presence?
Maybe the environmental conditions that allowed for humans to invent agriculture also spelled doom for the megafauna. If the world of relevant scientists agree that this is an open problem, it doesn't make sense to just pretend like we know the answer because it suits us in whatever manner.
The fact is: We don't know what killed off the megafauna.
>The fact is: We don't know what killed off the megafauna.
We also don't know that gravity works. All we know is that when we drop things they tend to end up on the floor. There have been enough experiments of isolated islands and continents being colonized by humans and having all their large animals go extinct within a century that the two are as correlated as anything we can expect in science.
The only reason to claim that humans are not the cause is an emotional one: to pretend that we have been at peace with nature in some mythical past. The alternative, that modern humans have always been an ecological disaster wherever they went, is not something that's palatable to many in the West since it means the noble savage wasn't.
> There have been enough experiments of isolated islands and continents being colonized by humans and having all their large animals go extinct within a century that the two are as correlated as anything we can expect in science.
So the vast majority of scientists who study this field are all enamored with an obviously false emotional claim, and are all crappy scientists. Except for you - who knows what really happened tens of thousands of years ago, because your gut tells you so.
So gravity fluctuates, I think in the 70's it was a little stronger, but the force changes depending on where you are on the planet anyway.
Saying that, if we are 10,000 years into a Mass Extinction, how many more years before we can start gene editing to bring back extinct animals like the Dodo?
I dont think we are more than a decade or two away from that, plus we are also now able to grow meat. Sure we havent solved the nuclear radiation problem for energy, but fusion seems to be close, I think the longest experiment was China running a fusion experiment for just over 15minutes.
So are we at the point where some of us can now actually play God!?!
The last known specimine of the dodo was stuffed on display at harvard library. It was burnt by a libriarian that thought it was attracting mites. So we have no source of dna to bring it back with last i read.
> The only reason to claim that humans are not the cause is an emotional one
False. 30+ genera vanished from North America in a geological instant, at the same time as the Clovis culture. Dire wolves, cheetahs, sabertooths, horses, camels, a bear much bigger than the grizzly, woolly mammoths, mastodons. A layer of platinum-enriched dust is left from that instant, with bones below and none above, Clovis points below, none above. Where do you imagine the Clovis people got all that platinum dust, and how did they scatter it all across the continent? And, where did they go after that?
Lions survived on the Greek mainland into the classical era, possibly eliminated finally by Romans.
Take all the elephants and lions and giraffe in Africa. Put them in North America. Where are they safe?
A few reserves maybe. In Africa they do mostly fine because there is a lot of undeveloped land. Develop the land and give a population a use for space, megafauna disappear. That’s what’s happening all over Africa now.
When Europeans arrived in the US, the climate stayed reasonably static for a long time but the animals disappeared. Is there another reason except humans?
I agree that 'the climate stayed reasonably static' in comparison to the ice ages, which is what the above thread is discussing.
But what's fascinating is that the arrival of Europeans in the US is hypothesized by some to have led to a dramatic cooling event called the "Little Ice Age".
Other researchers have supported depopulation in the Americas as a factor and have asserted that humans cleared considerable amounts of forest to support agriculture in the Americas before the arrival of Europeans brought on a population collapse.[134][135] Richard Nevle, Robert Dull and colleagues further suggested that not only anthropogenic forest clearance played a role in reducing the amount of carbon sequestered in Neotropical forests but also that human-set fires played a central role in reducing biomass in Amazonian and Central American forests before the arrival of the Europeans and the concomitant spread of diseases during the Columbian exchange.[136][137][138] Dull and Nevle calculated that reforestation in the tropical biomes of the Americas alone from 1500 to 1650 accounted for net carbon sequestration of 2-5 Pg.[137] Brierley conjectured that the European arrival in the Americas caused mass deaths from epidemic disease, which caused much abandonment of farmland. That caused much forest to return, which sequestered greater levels of carbon dioxide.
“Looking into alternative theories and making your own judgement” seems like code for “there are ways around uncomfortable feelings”. I accept we are absolutely brutal animals who have significantly altered Earth’s environment and the other life here which, per Darwin, differs by degree rather than by kind.
I don’t feel guilty about our past, and I accept my responsibility to do better (within my learned and adopted value-system where ecological diversity is important for resilience during inevitable change, and where the human story carries on unbroken for some arbitrary length of time. That seems meaningful, and maybe the best way is through culture and oral tradition?). It’s okay to feel whatever you’re feeling, and important to decide what to do next.
This is one of those topics I am more familiar with, and as such the number of users sharing superficial speculation as fact makes me wonder if the same is true on the topics I am not as familiar with.
Yes, that's what we always see, because megafauna are highly obvious in the fossil record. Tiny or especially soft-bodied invertebrates maybe not so much, and I'd hesitate to assume past mass extinctions provide too precise a model for one taking place in the present day. After all, there's nothing in the fossil record to suggest what a mass extinction might look like like in an environment containing modern humanity, too.
Are abstracts typically filled with this much editorial? I’m no climate science denier but adjectives like “sad” seem insanely out of place in something like this…
I agree; but is sadness any sort of scientific measure? Does it have any place in an abstract or a scientific study? I don’t think so. It seems weird to me.
It’s a three-letter glimpse into what motivated these scientists to write the paper; I think we can acknowledge it and move on without losing sight of scientific rigor.
Tt appears to be a pretty sound review of evidence, and then a discussion and conclusions section where the results of the review are interpreted and implications are discussed. Seeing "sad" appear in an abstract is sort of unusual. However in the discussion in the review the arguments about morality etc are a bit more sophisticated, but I reckon it isn't too odd to have a value claim on the implications of the review being unfortunate, since they have real implications for human wellbeing. If the same sentiment was couched in normal amounts of academic jargon, you would likely not have noticed.
I agree with this, and not sure why it is being downvoted. Another small part that jumps out:
>We take issue with these stances
I didn't realize science was about 'taking stances', I thought it was about conducting specific methodical experiments in an unbiased way to reach an unknown conclusion.
Taking issue with the positions of others is a perfectly normal part of the scientific process. I am not sure where your definition of 'what science is about' comes from but it can't possibly be true, if you think about it for a bit.
As to the votes, there's a specific guideline about that kind of comment:
Please don't pick the most provocative thing in an article or post to complain about in the thread. Find something interesting to respond to instead.
>Taking issue with the positions of others is a perfectly normal part of the scientific process.
Sure. I'm sure Copernicus took issue with the earth-centric position of the church. We all know who was correct in the end. I'm just saying that evoking emotion in the abstract of a paper seems a bit of a reach.
>can't possibly be true, if you think about it for a bit.
Hmm. I said that I thought science was about conducting experiments in an unbiased way to come to a conclusion. Maybe I was really way off base. I will think about it a bit more.
>As to the votes, there's a specific guideline about that kind of comment
I wasn't aware of this, so thanks for the input. I'm still not sure it applies here though. tjr225 was asking a question about the editorializing or emotion or whatever behind the abstract in a paper. I don't think its just picking something provocative to complain about, I think it's a legitimate concern about the infusion of emotion into science.
It applies because it's a microscopic part - literally one word - in a long detailed paper about something completely different. The issue isn't 'legitimacy' or even rightness (although I think the idea expressed in the comment is straight up wrong) - it's that it isn't particularly interesting or on topic. It requires a big leap into grandiosity to make it so - a single word in an abstract doesn't say anything about 'the infusion of emotion into science'.
Edit: Incidentally, 'Copernicus took issue with the church position' is, inadvertently, an oversimplification similar to the one you're making in 'how science works'. The 'Copernican Revolution' is a big topic in the history and philosophy of science. For a very short outline, scihub up
Hmm, alright. I feel like I understand where you are coming from, but I'm not sure you understand where I'm coming from. Yes, the original comment pointed out one word. But clearly there was more than just that one word that held the sentiment. It's like picking up a leaf from an oak tree and saying "it's an oak tree" and then you say "well, that was only one leaf".
Zooming out, and reading the abstract for a third time, I can clearly see the implicit bias. (I'm not saying people are wrong for how they feel, (I actually feel the same way) I'm just saying it's not science. Of course the rest of the paper may be a bunch of great science, but I, and others, are just asking to keep the emotion out of the lab.)
I only used the word 'sad' as an example... I can see how that is unclear. The entire abstract seemed very editorialized to me. And I feel the same way that you do, too.
Re-read the abstract; the word "sad" is only a facet of the editorialized nature of the thing.
But clearly there was more than just that one word that held the sentiment.
The comment doesn't show that, it just complains about the one word.
I can clearly see the implicit bias. [...] I'm just saying it's not science.
It's a big claim that's not much related to the post. Can it be an interesting topic of discussion? Absolutely. But the onus is on the commenter to support it, to make it interesting, to present some sort of argument, to spur some kind of interesting discussion. Throwaway comments about a single word don't do that which is why they are discouraged.
Of course science is about discussing stances. Conclusions and hypotheses are stances taken on an interpretation of data. The authors present data and demonstrate why a particular stance would be a misinterpretation.
> I thought it was about conducting specific methodical experiments in an unbiased way to reach an unknown conclusion.
How could you specify an experiment to conduct to test whether a conclusion is valid without an apriori examination of said conclusion (stance) and determining what evidence would support or refute it?
Claiming "I've seen such and such" is the textbook definition of the word "anecdote". Using that to justify a position is what we (all) call "anecdotal evidence."
Here is the ejaculatory fulfillment and affirmation you so deeply desire: You are technically correct!
Here is why it is HILARIOUS that you're being all rules lawyer: my basic complaint is that the article and the general attitude of humanity and capitalism toward environmentalism: pussyfooting around whether we are "technically" in a mass extinction when we have "technically" only caused the extinction of X gigantic morally indefensible quantity of species vs some other number that may be slightly less or more while also being morally indefensible.
It is plain as day doing a modicum of research that we have caused the unnecessary destruction of trillions? quadrillions? of organisms and likely millions of species. Between habitat destruction, agricultural industrialization, invasive species, climate change, and good old poaching and hunting: humans humans humans. We did it.
But your attitude are the reason humanity has fucked up the planet to this degree, and the profit-motive organizations have gotten away with it: obfuscation, FUD, placing impossible burden of proof on the environmentalists, lawyers forming twisted arguments and case law that is "legally correct", paying off politicians to pass laws that make the murder of species "legally correct". You are correct sir! Good job! Way to be CORRECT.
And am I any better? I'm a fucking American. My very existence makes me a massive part of the problem. I am massive piece of shit just by continuing to live, breathe, and shit.
Well, have your gold star. You have won this argument! But you have lost the war. We all have.
That's all good and well, but I've made no statements, no arguments, no dismissals or anything of the sort about anything you've said here. Whatever attitude you're attributing to me, I've said nothing to demonstrate at all. All I did was ask you if you dismiss peoples anecdotes as anecdotes. So do you?
Wouldn't it be best to act as if it's fact, even without definitive evidence one way or another? Otherwise it's like deciding to not drive cautiously on a mountain road because your GPS isn't sure if there's a sharp turn ahead.
Well the pandemic has shown us that even if the GPS is pretty sure there is a sharp turn ahead some people refuse to believe it because it is scary to drive on that sharp turn. Eventually we all will have to take that sharp turn but I just hope there is safe passage left ahead of that turn and not all downhill.
There will always be another thing to be afraid of. “ Wouldn't it be best to act as if it's fact,” will always be there as a question for the next thing.
So no, it wouldn’t be best to default to assuming the worst, you have to be able to decide which risks to tolerate and which to address, and to which degree.
Absolutely not! The only way that you can believe this is if you a) consider the preservation of human civilization to be approximately equal, in terms of significance to your decision making, to living a more comfortable life personally. In this instance, we are at war, and I have nothing to say to you, so you can stop reading. Or b) you are making a very serious error in your calculation.
Imagine that you the kind of immortal being that can still die in car crashes, but you never age. Whenever you take a risk, of death say, in order to get the expected utility of taking this risk, you need to multiply your risk ,which is a small number, by the opportunity cost of that risk, which is an infinite life's worth of utility. I do not, like many of the "rationalists" believe that this figure is infinity, but it is very obviously much larger than your risk is small. It's hard to reason about, but I urge you to imagine it in the shower with the lights off. Really try to get into that space, and imagine what risks you would consider to be acceptable as an immortal.
Humanity is such an immortal being, but it currently lacks the tools to act for itself. We can build those tools, but that will take time and lots and lots of thought.
>Wouldn't it be best to act as if it's fact, even without definitive evidence one way or another? Otherwise it's like deciding to not drive cautiously on a mountain road because your GPS isn't sure if there's a sharp turn ahead.
Because since basically forever, people have been claiming doomsday based on nothing. Mayan calendar!
Obviously this is climate change related so lets just stick with climate change doomsdays.
Lets just look at that last one. The rationalization seems sound. So much more energy in the oceans would seem to suggest it would give more power to hurricanes. but the exact opposite of the prediction happened.
Al Gore invested $ in renewables, he will profit greatly when we switch over. However, as an evangelist, he may be exagerating the doom and gloom a lot.
How many of these claims had the support of thousands of reputable scientists backed up by uncountable studies? What you are linking are individual studies or ancient history, not the aggregate of research which says that climate change and human encroachment are causing oceans to rise, species to disappear, top soil to disappear, fish stocks to dwindle, and the air we breath and water we drink to become increasingly polluted. Salon, Breitbart, The Guardian, Forbes, Al Gore, Oprah, Snopes and the Independent you linked are not reliable sources.
>How many of these claims had the support of thousands of reputable scientists backed up by uncountable studies?
Virtually all of them? These are often still claims made today. The common retort to this is to say 'See how dire it has been for decades!'
>What you are linking are individual studies or ancient history,
Lets take John Stossel for example, he made the counter claim that we have not had an increase in severity to hurricanes and other similar weather. He got fact checked as false. So absolutely not ancient history.
>not the aggregate of research which says that climate change
5 hiroshima nuclear bombs a second! Except that claim is also true during the coldest day of the last ice age because that energy equivalency is coming from the sun.
>uman encroachment are causing oceans to rise, species to disappear, top soil to disappear, fish stocks to dwindle, and the air we breath and water we drink to become increasingly polluted.
The sea levels greatly increased about 7000-8000 years ago. Most likely this is the source of stories like Noahs ark and atlantis going under water. From about 6000 years ago to today it has risen at exactly the same rate. In fact Al Gore's false claim that florida would be under water was in part due to 'icecaps melting' as well as that standard rate of rise. Yet despite the icecaps melting Florida remains...
Species disappearing is a concern to be sure. Not really climate change related at all. Human sprawl and destruction of natural habitats is a problem. We should do more about this.
Top soil disappearing is a gigantic problem. Like beyond immense. I have researched extensively around regenerative farming, vertical farming, aquaponics. Here's the thing... climate change is actually helping in for this problem. This problem is entirely being caused by immoral farming. We must greatly increase the amount of animal farming is occurring. Get back to pasture raised animals.
Fish stocks are another big concern of mine as a hobby fisherman. This is entirely due to commercial over fishing. We should do something about this. However blaming climate change for this is missing the target.
>. Salon, Breitbart, The Guardian, Forbes, Al Gore, Oprah, Snopes and the Independent you linked are not reliable sources.
Are you asserting climate change proponents didnt make these claims in history? That would be a fallacy.
That book really hit home for me the insignificance of human versus
planetary timescales. For all our handwringing about global warming,
we're actually in an ice age. Even if we solve climate change, the
earth will continue to witness unfathomably long geologic eras long
after we're gone.
Yes and no. The planet is middle aged. If we burn everything down to nothing again, the Earth only has one or two regenerative cycles left (where it can go from simple organisms up to things as complex as mammals again based on how long that took) in it before the sun's slow increase in brightness evaporates the oceans making complex life impossible in about 1.1 billion years. We can really do some damage to the lifecycle of this planet. It took about 2 billion years to go from RNA world to today.
Call me an anthropomorphic narcissist, but I can barely manage concern for my descendants a hundred years from now, much less the carbon-based morlocks scampering around a hundred thousand years from now.
While it seems likely life is located elsewhere in the universe, it seems to me we should be good stewards of the one little mote of dust where we know for sure it exists.
I don't have a particularly good grip on how long a million years is, but I suspect it's still better than yours.
A million years is less than a week in the Earth's lifetime. The virus of humanity can do its darnedest but the planet isnt going to remember a mild cold.
When I was a kid, I always thought that where I grew up (southern Indiana) was basically a forest and that the farms and towns and roads that I saw were just "nestled" in the forest. That's because everywhere you look, there's almost always a line of trees on the horizon. Not being particularly mountainous, or even hilly, it looks from a distance like the tree line is the "forest". In pretty much every direction. I was a boy scout, and we did a lot of camping at various parks. I really didn't know exactly where I was, I just thought we were out in the "forest".
It's a trick of perspective. I had never really seen my local area from the sky until about 2000. Now, Google Earth can show you the whole thing, at zoomable resolution.
Boy, was I wrong. Not only is southern Indiana mostly not forest, it's mostly farms, roads, and fields, and towns, with only scattered lines and splotches of trees. In reality, those boy scout trips were basically in nature preserves and national forests, the few remaining places of actual forest. Human habitation has absolutely decimated the forest...across the entire midwest. And the many millions, billions of animals that lived in the forest, they're gone, numbers dwindled, or exinct. Bears and big cats and wolves and elk....almost all gone here. Not to mention the intricate ecosystems full of life, from squirrels down to insects and ants...uncountable the individual living things that have been absolutely obliterated by our hunger.
Just take a look at Google Earth, switch to satellite mode, turn off all labels, and take in the vast green patchwork of farms that stretches for a thousand miles in every direction in the middle of North America. There is precious else but farm and city and road.
A lot of my social circle is farmers or children of farmers, and they almost universally consider the farm to be "nature" or at least a close enough thing to nature. I think society just kinda decided that nature is "not city" and that attitude is holding back progress.
Your natural history is way off. There's no trees on the prarie because it's dryer than the surrounding area and the grass fires burn the saplings before they grow. The climate of the interior US doesn't mesh well with forests.
I think you're overconfident in your understanding here. It's a very complex subject. Removal of trees from an area of land will result in greater dryness. Trees, in a substantial way, create their own climate and can increase precipitation.
I'm aware, but where are you getting your knowledge specifically of the American plains? They were called the great plains since the founding of the country, because the settlers encountered plains, because they've been plains for approximately 25 million years: https://en.wikipedia.org/wiki/Great_Plains.
I'm certainly no expert on the Great Plains but for a decent understanding of its vegetation history I wouldn't turn to wikipedia but instead look to see if there have been any decent pollen analyses done. After a short search I found one study [1] that said:
> Nonarboreal pollen comprises between 37% and 86% of the assemblage
throughout the record with the largest percentages occurring during the mid-Holocene (~8000–4000 yr BP). The pollen record also suggests that
at 8200 yr BP, there was an abrupt shift from oak-elm woodland to a more open landscape of grassland or savanna, which remained through out the
mid-Holocene. Additionally, the pollen data suggest that vegetation composition exhibited little change in diversity through time despite recurring fire.
Charcoal concentrations varied from 30 to nearly 1200particles cm−3, indicating changes in relative amount of biomass burned, but the morphotypes of
charcoal pieces indicate that woody fuels persisted during the mid-Holocene despite the apparent grassland-dominated landscape. Magnetic susceptibility
in the sediment ranges from −0.9 to 22.4 (×10−5 SI) throughout the record, with the biggest increase occurring as the vegetation shifted from woodland
to grassland entering the mid-Holocene.
So I'd suggest that the change from oak-elm woodland to more open grassland or savanna was possibly (probably?) precipitated by the arrival of humans in North America.
Very interesting, I'll take another look. However if we take the paper at face value circa 8200BP there was some widespread climate event which is likely what drove the change, not people.
Why I consider this paper suspect is that the mechanism that drives the modern preservation of the prarie and sometimes its encroachment into existing woodland is well understood. It doesn't require the involvement of people. It does not exist today because the grassland is gone. Lightning during the drier days of fall would lead to grass fires, burning the trees. There were microenvirons near streams that had trees but they were not common.
I don't think you can say the paper is 'suspect'. It's primarily factual findings of a pollen analysis. But a criticism you certainly can make is that it's just one study from one geographic location. And that's a very valid criticism and looking back, I am guilty of over-extrapolating from this one single study in one location.
> Lightning during the drier days of fall would lead to grass fires, burning the trees.
This is one dynamic. There are other dynamics that help (not hinder) the expansion of forests. So again, I don't think the story is so simple.
> There were microenvirons near streams that had trees but they were not common.
Australia also has microenvirons along water courses where tropical & temperate rainforest species are preserved. Rainforest species are much more resistant to fire as opposed to the very fire-prone (but also fire adaptive) Eucalypt species that are highly dominant across the Australian landscape. But this is a change since the arrival of man, when rainforest and other less fire-prone tree species were much more predominant. In other words, fire-prone but also fire-adaptive trees/forests were 'selected for' by humans in Australia. Trees along streams on the North American Great Plains could also just be remnants of earlier much more wide-spread forests.
So you can see that I'm continuing to push the influence of humans in the diminution of forests. In many ways humans are 'the enemy' of forests (with the exception of some rainforest tribes that are highly adapted for forest living). Anyway, it's a very interesting topic and I've appreciated this exchange of views.
Plenty of other animals will destroy trees to keep the plains the way they are. Pretty much any large mammal will trample saplings and rub up against larger trees until they die. This is easier to see on the African plains with elephants.
Indiana’s deforestation has been pretty incredible. Historically about 90% of land-cover in IN was forest, that fell to something like 10% by 1900, but has since crawled upwards. Today, something like a quarter of IN is forested.
Elsewhere in the Midwest, ecological destruction has had a rather different tune. Tallgrass prairies used to stretch from Northern Texas, to Chicago, to Minneapolis, all the way up into Manitoba. Tallgrass prairie doesn’t really exist anymore, except for a fairly narrow strip running through eastern Kansas into the very corner of NE Oklahoma. This area is home to the Flint Hills, which happened to be too rocky to till & convert into farmland. About 4% of the original extent of Tallgrass Prairie remains. Even this portion is under threat. Tallgrass prairie is maintained by the vast wildfires that used to sweep across the Great Plains— there’s few barriers out here, so a lightning strike during a windy storm could easily trigger a wildfire that swept across hundreds of miles of prairie. Native Americans in the region would also periodically burn swathes of prairie to improve visibility (bison hunting) and renew the lands. Without regular burns, prairie quickly will be overtaken by shrubs and primary successional trees (mostly Red Cedar where I’m at). Within only a few years, the land will no longer resemble Tallgrass prairie, but rather a shrubby wasteland. Regular grazing is also essential for triggering the flowering of the full range of native wildflowers. Cows have replaced buffalo in this region, although their hooves do a fine job of approximating the topsoil-disrupting effects of buffalo grazing, a buffalo’s hooves are more acutely scooped and are needed to unlock the full majesty of Tallgrass prairie floral diversity.
Although I’ve spent most of my life splitting time between the Appalachians and the Rockies, the infinite expanse of undulating green earth that one can see in the mid-summer Flint Hills is probably the most special landscape I have ever witnessed. No other place feels are unfamiliar, or alien, or verdant, or melodic, or uncomplicated. I would recommend to all a drive through Chase County, KS, where you will stare into the horizon and see nothing but a azure amphitheater atop a boundless emerald sheet, and the silhouettes of a few distant cattle peppered at their margin.
I like to bring this up, but 8,000 years ago half of North America was under ice. That means that every living creature in that region didn’t exist. Every creature unique to those regions came about in the last 8,000 years.
1. I think evolution happens much faster than people realize
2. Extinctions happen more quickly than people realize
3. Humans likely were the cause of many extinctions through pollution and cultivation. But other animals and plants are currently filling the niche and containing to expand.
I would really like to understand the distribution of species over the last 10k, 100k, 250k, 1m years. We simply don’t have great data so it’s really hard to say. What I can say, is that there’s a ton of life. Life doesn’t appear to have diminished much on a whole. Which is comforting, at the very least.
> Life doesn’t appear to have diminished much on a whole.
There are a lot more humans now, and a lot more cows, sheep and hogs. There's much less of everything else, from the bottom on up. I think where it is easy to see is in the drastic decline in small and large mammals, other than humans, cows, sheep and hogs. Once you see that, maybe you'll notice, just in your own lifetime, the massive decline in bird species and populations. Maybe you'll notice when you drive around at night in the Summer you no longer have a windshield covered in dead bugs. I haven't see a real frog in years.
Unless you're satisfied with merely diverse species of bacteria and other simple life forms for the next X billons of years, you should be startled at how astoundingly quickly Earth's amazing diversity of life has declined from whatever it's most recent peak was before the development of civilization, or before the Babylonians, before the Greeks, before the Romans, before the Industrial Revolution, and before the Chemical Revolution. Don't you ever wonder just how many whales there were before the first whalers? Or how many tuna or salmon there once were? Reports from Colonial times on bird populations aren't very specific, but at certain times of years, the number of geese alone in Virginia used to darken the sky. They didn't just shoot down one goose at a time, they used giant guns that took hundreds at a time. Maybe we don't do it with big guns, but we are basically poisoning everything on the planet to death. So maybe the amount of biomass stays the same, but who wants a planet of poison goo?
The last time half of North America was under ice was 20kya, 8kya was relatively warm with just a bit of ice that hadn't melted yet in the northeast of Canada.
The species that entered those areas would have done so during climate-driven redistributions from the south as entire plant and animal communities moved north to fill new available habitat, and while there would have been some local adaptation, it isn't like they all evolved from vastly different ancestors in 20k years.
> But other animals and plants are currently filling the niche and containing to expand.
Sort of. For example, the main thing that has filled the niche of predator of grazers like deer across eastern North America is probably the automobile.
In terms of biomass, yes there's a lot of domestic animals. But in terms of functional diversity, there has been a great decline. Just think of the difference between prarie and a crop monoculture. The fewer species in each guild that interact to form the ecosystem, the less resilience overall. Despite large amounts of biomass, the loss of biodiversity is undeniably an issue.
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[ 3.0 ms ] story [ 167 ms ] threadThat would suggest we're 10,000 years into one, rather than being at the early stages of it.
there are rumblings that the ~10k year ago megafauna die off was far too rapid to have been done by relatively unsophisticated humans and is likely to have been caused by a comet fragment impact or similar.
https://en.wikipedia.org/wiki/Younger_Dryas_impact_hypothesi...
Genetically, not too much. In terms of population density and technology, we absolutely have changed, and both are relevant to our ability to clear a continent of dozens of species of animals at a rapid rate.
Maybe the environmental conditions that allowed for humans to invent agriculture also spelled doom for the megafauna. If the world of relevant scientists agree that this is an open problem, it doesn't make sense to just pretend like we know the answer because it suits us in whatever manner.
The fact is: We don't know what killed off the megafauna.
Rhinos in Africa were killed off for asian medicinal customers.
We also don't know that gravity works. All we know is that when we drop things they tend to end up on the floor. There have been enough experiments of isolated islands and continents being colonized by humans and having all their large animals go extinct within a century that the two are as correlated as anything we can expect in science.
The only reason to claim that humans are not the cause is an emotional one: to pretend that we have been at peace with nature in some mythical past. The alternative, that modern humans have always been an ecological disaster wherever they went, is not something that's palatable to many in the West since it means the noble savage wasn't.
Come on
I will double down and die on this hill. You cannot compare your confidence in this theory to the fundamental physical laws.
Saying that, if we are 10,000 years into a Mass Extinction, how many more years before we can start gene editing to bring back extinct animals like the Dodo?
I dont think we are more than a decade or two away from that, plus we are also now able to grow meat. Sure we havent solved the nuclear radiation problem for energy, but fusion seems to be close, I think the longest experiment was China running a fusion experiment for just over 15minutes.
So are we at the point where some of us can now actually play God!?!
False. 30+ genera vanished from North America in a geological instant, at the same time as the Clovis culture. Dire wolves, cheetahs, sabertooths, horses, camels, a bear much bigger than the grizzly, woolly mammoths, mastodons. A layer of platinum-enriched dust is left from that instant, with bones below and none above, Clovis points below, none above. Where do you imagine the Clovis people got all that platinum dust, and how did they scatter it all across the continent? And, where did they go after that?
Lions survived on the Greek mainland into the classical era, possibly eliminated finally by Romans.
A few reserves maybe. In Africa they do mostly fine because there is a lot of undeveloped land. Develop the land and give a population a use for space, megafauna disappear. That’s what’s happening all over Africa now.
When Europeans arrived in the US, the climate stayed reasonably static for a long time but the animals disappeared. Is there another reason except humans?
But what's fascinating is that the arrival of Europeans in the US is hypothesized by some to have led to a dramatic cooling event called the "Little Ice Age".
Quoting from the wikipedia article: https://en.wikipedia.org/wiki/Little_Ice_Age#Decreased_human...
Other researchers have supported depopulation in the Americas as a factor and have asserted that humans cleared considerable amounts of forest to support agriculture in the Americas before the arrival of Europeans brought on a population collapse.[134][135] Richard Nevle, Robert Dull and colleagues further suggested that not only anthropogenic forest clearance played a role in reducing the amount of carbon sequestered in Neotropical forests but also that human-set fires played a central role in reducing biomass in Amazonian and Central American forests before the arrival of the Europeans and the concomitant spread of diseases during the Columbian exchange.[136][137][138] Dull and Nevle calculated that reforestation in the tropical biomes of the Americas alone from 1500 to 1650 accounted for net carbon sequestration of 2-5 Pg.[137] Brierley conjectured that the European arrival in the Americas caused mass deaths from epidemic disease, which caused much abandonment of farmland. That caused much forest to return, which sequestered greater levels of carbon dioxide.
Because they evolved with us and evolved to respect the threat we pose.
I don’t feel guilty about our past, and I accept my responsibility to do better (within my learned and adopted value-system where ecological diversity is important for resilience during inevitable change, and where the human story carries on unbroken for some arbitrary length of time. That seems meaningful, and maybe the best way is through culture and oral tradition?). It’s okay to feel whatever you’re feeling, and important to decide what to do next.
>We take issue with these stances
I didn't realize science was about 'taking stances', I thought it was about conducting specific methodical experiments in an unbiased way to reach an unknown conclusion.
(edit: something something appeal to emotion)
As to the votes, there's a specific guideline about that kind of comment:
Please don't pick the most provocative thing in an article or post to complain about in the thread. Find something interesting to respond to instead.
Sure. I'm sure Copernicus took issue with the earth-centric position of the church. We all know who was correct in the end. I'm just saying that evoking emotion in the abstract of a paper seems a bit of a reach.
>can't possibly be true, if you think about it for a bit.
Hmm. I said that I thought science was about conducting experiments in an unbiased way to come to a conclusion. Maybe I was really way off base. I will think about it a bit more.
>As to the votes, there's a specific guideline about that kind of comment
I wasn't aware of this, so thanks for the input. I'm still not sure it applies here though. tjr225 was asking a question about the editorializing or emotion or whatever behind the abstract in a paper. I don't think its just picking something provocative to complain about, I think it's a legitimate concern about the infusion of emotion into science.
Edit: Incidentally, 'Copernicus took issue with the church position' is, inadvertently, an oversimplification similar to the one you're making in 'how science works'. The 'Copernican Revolution' is a big topic in the history and philosophy of science. For a very short outline, scihub up
https://physicstoday.scitation.org/doi/10.1063/1.2825071
Copernicus wouldn't qualify as science under your definition of what science is about either.
Zooming out, and reading the abstract for a third time, I can clearly see the implicit bias. (I'm not saying people are wrong for how they feel, (I actually feel the same way) I'm just saying it's not science. Of course the rest of the paper may be a bunch of great science, but I, and others, are just asking to keep the emotion out of the lab.)
Re-read the abstract; the word "sad" is only a facet of the editorialized nature of the thing.
The comment doesn't show that, it just complains about the one word.
I can clearly see the implicit bias. [...] I'm just saying it's not science.
It's a big claim that's not much related to the post. Can it be an interesting topic of discussion? Absolutely. But the onus is on the commenter to support it, to make it interesting, to present some sort of argument, to spur some kind of interesting discussion. Throwaway comments about a single word don't do that which is why they are discouraged.
> I thought it was about conducting specific methodical experiments in an unbiased way to reach an unknown conclusion.
How could you specify an experiment to conduct to test whether a conclusion is valid without an apriori examination of said conclusion (stance) and determining what evidence would support or refute it?
But by all means, let's waste another 10 years sending it back to committee, for review and debate and bikeshedding semantics.
Claiming "I've seen such and such" is the textbook definition of the word "anecdote". Using that to justify a position is what we (all) call "anecdotal evidence."
Here is why it is HILARIOUS that you're being all rules lawyer: my basic complaint is that the article and the general attitude of humanity and capitalism toward environmentalism: pussyfooting around whether we are "technically" in a mass extinction when we have "technically" only caused the extinction of X gigantic morally indefensible quantity of species vs some other number that may be slightly less or more while also being morally indefensible.
It is plain as day doing a modicum of research that we have caused the unnecessary destruction of trillions? quadrillions? of organisms and likely millions of species. Between habitat destruction, agricultural industrialization, invasive species, climate change, and good old poaching and hunting: humans humans humans. We did it.
But your attitude are the reason humanity has fucked up the planet to this degree, and the profit-motive organizations have gotten away with it: obfuscation, FUD, placing impossible burden of proof on the environmentalists, lawyers forming twisted arguments and case law that is "legally correct", paying off politicians to pass laws that make the murder of species "legally correct". You are correct sir! Good job! Way to be CORRECT.
And am I any better? I'm a fucking American. My very existence makes me a massive part of the problem. I am massive piece of shit just by continuing to live, breathe, and shit.
Well, have your gold star. You have won this argument! But you have lost the war. We all have.
So no, it wouldn’t be best to default to assuming the worst, you have to be able to decide which risks to tolerate and which to address, and to which degree.
Imagine that you the kind of immortal being that can still die in car crashes, but you never age. Whenever you take a risk, of death say, in order to get the expected utility of taking this risk, you need to multiply your risk ,which is a small number, by the opportunity cost of that risk, which is an infinite life's worth of utility. I do not, like many of the "rationalists" believe that this figure is infinity, but it is very obviously much larger than your risk is small. It's hard to reason about, but I urge you to imagine it in the shower with the lights off. Really try to get into that space, and imagine what risks you would consider to be acceptable as an immortal.
Humanity is such an immortal being, but it currently lacks the tools to act for itself. We can build those tools, but that will take time and lots and lots of thought.
Because since basically forever, people have been claiming doomsday based on nothing. Mayan calendar!
Obviously this is climate change related so lets just stick with climate change doomsdays.
~1969, The UK won't exist in 2000 ~1970, food and water rationing by 1980s ~1975, new ice age upon us. ~1988, NYC under water in the 2000s: https://web.archive.org/web/20110202162233/https://www.salon... ~1989, entire nations wiped off the planet by global warming: https://www.snopes.com/fact-check/nations-vanish-global-warm... ~2000, snowfall a thing of the past: https://web.archive.org/web/20150912124604/http://www.indepe...
Might I interject, I have 30cm of snow coming in the next couple days. Mmmm Canada.
~2005, 50 million climate change refugees by 2010: https://www.theguardian.com/environment/2005/oct/12/naturald... ~2006, Super hurricanes! https://www.breitbart.com/the-media/2015/06/01/media-fail-no...
Lets just look at that last one. The rationalization seems sound. So much more energy in the oceans would seem to suggest it would give more power to hurricanes. but the exact opposite of the prediction happened.
~2006, inconvenient truth by al gore? Except the title it a lie. Virtually every one of his claims have been falsified now. https://www.oprah.com/g/image-resizer?width=670&link=http://...
Yes that's al gore in the inconvenient truth predicting florida significantly under water, years ago.
What is the motivation behind Al gore's false claims?
https://www.forbes.com/sites/jeffmcmahon/2015/12/03/al-gore-...
Al Gore invested $ in renewables, he will profit greatly when we switch over. However, as an evangelist, he may be exagerating the doom and gloom a lot.
Virtually all of them? These are often still claims made today. The common retort to this is to say 'See how dire it has been for decades!'
>What you are linking are individual studies or ancient history,
Lets take John Stossel for example, he made the counter claim that we have not had an increase in severity to hurricanes and other similar weather. He got fact checked as false. So absolutely not ancient history.
>not the aggregate of research which says that climate change
Let's get each other back on the same page. I do not deny climate change. I deny the alarmism. The claims like this: https://www.cnn.com/2020/01/13/world/climate-change-oceans-h...
5 hiroshima nuclear bombs a second! Except that claim is also true during the coldest day of the last ice age because that energy equivalency is coming from the sun.
>uman encroachment are causing oceans to rise, species to disappear, top soil to disappear, fish stocks to dwindle, and the air we breath and water we drink to become increasingly polluted.
Humans aren't causing the oceans to rise. https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/images/119/...
The sea levels greatly increased about 7000-8000 years ago. Most likely this is the source of stories like Noahs ark and atlantis going under water. From about 6000 years ago to today it has risen at exactly the same rate. In fact Al Gore's false claim that florida would be under water was in part due to 'icecaps melting' as well as that standard rate of rise. Yet despite the icecaps melting Florida remains...
Species disappearing is a concern to be sure. Not really climate change related at all. Human sprawl and destruction of natural habitats is a problem. We should do more about this.
Top soil disappearing is a gigantic problem. Like beyond immense. I have researched extensively around regenerative farming, vertical farming, aquaponics. Here's the thing... climate change is actually helping in for this problem. This problem is entirely being caused by immoral farming. We must greatly increase the amount of animal farming is occurring. Get back to pasture raised animals.
Fish stocks are another big concern of mine as a hobby fisherman. This is entirely due to commercial over fishing. We should do something about this. However blaming climate change for this is missing the target.
>. Salon, Breitbart, The Guardian, Forbes, Al Gore, Oprah, Snopes and the Independent you linked are not reliable sources.
Are you asserting climate change proponents didnt make these claims in history? That would be a fallacy.
https://en.wikipedia.org/wiki/Future_of_Earth#Loss_of_oceans
A million years is less than a week in the Earth's lifetime. The virus of humanity can do its darnedest but the planet isnt going to remember a mild cold.
It's a trick of perspective. I had never really seen my local area from the sky until about 2000. Now, Google Earth can show you the whole thing, at zoomable resolution.
Boy, was I wrong. Not only is southern Indiana mostly not forest, it's mostly farms, roads, and fields, and towns, with only scattered lines and splotches of trees. In reality, those boy scout trips were basically in nature preserves and national forests, the few remaining places of actual forest. Human habitation has absolutely decimated the forest...across the entire midwest. And the many millions, billions of animals that lived in the forest, they're gone, numbers dwindled, or exinct. Bears and big cats and wolves and elk....almost all gone here. Not to mention the intricate ecosystems full of life, from squirrels down to insects and ants...uncountable the individual living things that have been absolutely obliterated by our hunger.
Just take a look at Google Earth, switch to satellite mode, turn off all labels, and take in the vast green patchwork of farms that stretches for a thousand miles in every direction in the middle of North America. There is precious else but farm and city and road.
> Nonarboreal pollen comprises between 37% and 86% of the assemblage throughout the record with the largest percentages occurring during the mid-Holocene (~8000–4000 yr BP). The pollen record also suggests that at 8200 yr BP, there was an abrupt shift from oak-elm woodland to a more open landscape of grassland or savanna, which remained through out the mid-Holocene. Additionally, the pollen data suggest that vegetation composition exhibited little change in diversity through time despite recurring fire. Charcoal concentrations varied from 30 to nearly 1200particles cm−3, indicating changes in relative amount of biomass burned, but the morphotypes of charcoal pieces indicate that woody fuels persisted during the mid-Holocene despite the apparent grassland-dominated landscape. Magnetic susceptibility in the sediment ranges from −0.9 to 22.4 (×10−5 SI) throughout the record, with the biggest increase occurring as the vegetation shifted from woodland to grassland entering the mid-Holocene.
So I'd suggest that the change from oak-elm woodland to more open grassland or savanna was possibly (probably?) precipitated by the arrival of humans in North America.
[1] https://www.researchgate.net/profile/Berangere-Leys/publicat...
Why I consider this paper suspect is that the mechanism that drives the modern preservation of the prarie and sometimes its encroachment into existing woodland is well understood. It doesn't require the involvement of people. It does not exist today because the grassland is gone. Lightning during the drier days of fall would lead to grass fires, burning the trees. There were microenvirons near streams that had trees but they were not common.
> Lightning during the drier days of fall would lead to grass fires, burning the trees.
This is one dynamic. There are other dynamics that help (not hinder) the expansion of forests. So again, I don't think the story is so simple.
> There were microenvirons near streams that had trees but they were not common.
Australia also has microenvirons along water courses where tropical & temperate rainforest species are preserved. Rainforest species are much more resistant to fire as opposed to the very fire-prone (but also fire adaptive) Eucalypt species that are highly dominant across the Australian landscape. But this is a change since the arrival of man, when rainforest and other less fire-prone tree species were much more predominant. In other words, fire-prone but also fire-adaptive trees/forests were 'selected for' by humans in Australia. Trees along streams on the North American Great Plains could also just be remnants of earlier much more wide-spread forests.
So you can see that I'm continuing to push the influence of humans in the diminution of forests. In many ways humans are 'the enemy' of forests (with the exception of some rainforest tribes that are highly adapted for forest living). Anyway, it's a very interesting topic and I've appreciated this exchange of views.
Elsewhere in the Midwest, ecological destruction has had a rather different tune. Tallgrass prairies used to stretch from Northern Texas, to Chicago, to Minneapolis, all the way up into Manitoba. Tallgrass prairie doesn’t really exist anymore, except for a fairly narrow strip running through eastern Kansas into the very corner of NE Oklahoma. This area is home to the Flint Hills, which happened to be too rocky to till & convert into farmland. About 4% of the original extent of Tallgrass Prairie remains. Even this portion is under threat. Tallgrass prairie is maintained by the vast wildfires that used to sweep across the Great Plains— there’s few barriers out here, so a lightning strike during a windy storm could easily trigger a wildfire that swept across hundreds of miles of prairie. Native Americans in the region would also periodically burn swathes of prairie to improve visibility (bison hunting) and renew the lands. Without regular burns, prairie quickly will be overtaken by shrubs and primary successional trees (mostly Red Cedar where I’m at). Within only a few years, the land will no longer resemble Tallgrass prairie, but rather a shrubby wasteland. Regular grazing is also essential for triggering the flowering of the full range of native wildflowers. Cows have replaced buffalo in this region, although their hooves do a fine job of approximating the topsoil-disrupting effects of buffalo grazing, a buffalo’s hooves are more acutely scooped and are needed to unlock the full majesty of Tallgrass prairie floral diversity.
Although I’ve spent most of my life splitting time between the Appalachians and the Rockies, the infinite expanse of undulating green earth that one can see in the mid-summer Flint Hills is probably the most special landscape I have ever witnessed. No other place feels are unfamiliar, or alien, or verdant, or melodic, or uncomplicated. I would recommend to all a drive through Chase County, KS, where you will stare into the horizon and see nothing but a azure amphitheater atop a boundless emerald sheet, and the silhouettes of a few distant cattle peppered at their margin.
1. I think evolution happens much faster than people realize
2. Extinctions happen more quickly than people realize
3. Humans likely were the cause of many extinctions through pollution and cultivation. But other animals and plants are currently filling the niche and containing to expand.
I would really like to understand the distribution of species over the last 10k, 100k, 250k, 1m years. We simply don’t have great data so it’s really hard to say. What I can say, is that there’s a ton of life. Life doesn’t appear to have diminished much on a whole. Which is comforting, at the very least.
There are a lot more humans now, and a lot more cows, sheep and hogs. There's much less of everything else, from the bottom on up. I think where it is easy to see is in the drastic decline in small and large mammals, other than humans, cows, sheep and hogs. Once you see that, maybe you'll notice, just in your own lifetime, the massive decline in bird species and populations. Maybe you'll notice when you drive around at night in the Summer you no longer have a windshield covered in dead bugs. I haven't see a real frog in years.
Unless you're satisfied with merely diverse species of bacteria and other simple life forms for the next X billons of years, you should be startled at how astoundingly quickly Earth's amazing diversity of life has declined from whatever it's most recent peak was before the development of civilization, or before the Babylonians, before the Greeks, before the Romans, before the Industrial Revolution, and before the Chemical Revolution. Don't you ever wonder just how many whales there were before the first whalers? Or how many tuna or salmon there once were? Reports from Colonial times on bird populations aren't very specific, but at certain times of years, the number of geese alone in Virginia used to darken the sky. They didn't just shoot down one goose at a time, they used giant guns that took hundreds at a time. Maybe we don't do it with big guns, but we are basically poisoning everything on the planet to death. So maybe the amount of biomass stays the same, but who wants a planet of poison goo?
The species that entered those areas would have done so during climate-driven redistributions from the south as entire plant and animal communities moved north to fill new available habitat, and while there would have been some local adaptation, it isn't like they all evolved from vastly different ancestors in 20k years.
> But other animals and plants are currently filling the niche and containing to expand.
Sort of. For example, the main thing that has filled the niche of predator of grazers like deer across eastern North America is probably the automobile.
In terms of biomass, yes there's a lot of domestic animals. But in terms of functional diversity, there has been a great decline. Just think of the difference between prarie and a crop monoculture. The fewer species in each guild that interact to form the ecosystem, the less resilience overall. Despite large amounts of biomass, the loss of biodiversity is undeniably an issue.