Earth system impacts of the Great Dying in the Americas after 1492 (2019) | Hacker News Reader

Earth system impacts of the Great Dying in the Americas after 1492 (2019)

sciencedirect.com

54 pointsbenbreen28 comments

This is a tenuous correlation between human activity and CO2 emissions (which imo are questionable due to sampling errors).

The variance in CO2 measurements are within the range of random noise.

https://www.e-education.psu.edu/earth103/node/1018

That said, clearly nature overtakes the regions no-longer inhabited. That said it doesn’t seem to have impacted global temperatures in any meaningful ways based on the papers own questionable arguments.

Look at the first paragraph:

> decline in global atmospheric CO2 concentration by 7–10 ppm in the late 1500s and early 1600s which globally lowered surface air temperatures by 0.15∘C

For reference, the CO2 concentration was between 280-290 ppm at that time (from ice core samples, which arguably are somewhat regionally specific). It’s around 400ppm today. A 7ppm drop is within the expected range, likely even something you may see within one years standard fluctuations (today, anyway).

https://gml.noaa.gov/ccgg/trends/weekly.html

This paper is effectively not stating anything meaningful.

Seasonal CO2 fluctuations are quite large

https://de.wikipedia.org/wiki/Datei:Mauna_Loa_CO2_monthly_me...

IIRC, many Native American cultures practiced large scale controlled burning of prairies and forests in North America. So yeah, you'd expect that after their societies collapsed, their massive CO2 emissions would disappear. Interesting to see people in the comments who have no idea about pre-Colombian history in the Americas.

This is hacker news - many of us spend our day job spouting BS to look smart. :)

> "7.4 Pg C uptake"

7.4 Pg = 7.4 GT. That seems to correspond to about 3-4 ppm? But the paper says twice that. Is this just a volume vs. mass mixup? A CO2 molecule weighs half again the O2 and N2 molecules.

There is evidence of massive re-forestation in the Amazon a couple of centuries earlier, about coincident with a historically attested huge expedition from Africa a few decades before the Black Plague struck of Europe. But Spanish observers reported massive population on their first trip through, discounted because subsequent visits didn't find it. So maybe there was a previous pulse of carbon uptake, added to.

Amazonians were actively breeding trees for desired characters by 10000ya. About all we have left for physical proof is earthen causeways many miles long that would have enabled foot traffic when the basin flooded, and circular dikes around orchards that would have been closed to retain water when the flood started to recede. And "terra preta", patches of almost magically fertile soil.

Imagine death on such a scale that the forest reclaims so much land that the atmosphere changes. That was colonization…

That wasn't colonization, that was just accident. The diseases began their spread and began to destroy populations during the very early exploration phase, before any land was ever forcefully taken. For example, IIRC, the second Spanish expedition of interior North America found a dramatically diminished population from the first Spanish expedition, with neither expedition attempting to settle lands or otherwise intended to be hostile.

The claimed biological warfare incidents are 1) not well supported by evidence, but in any event 2) came much later in colonization, which was a multi-century process, BTW. Biological warfare is mostly a boogeyman, anyhow; something that in the 21st century we personally find most scary because modern people in mature industrial countries are unable to conceive of the raw, physical, individualized brutality of the actual conquests. Brutality to modern society means indiscriminate, technologically mediated, arms-length terrorism in the manner of something like biological warfare, so in the culture wars over historical narrative that's what one side uses as its sales pitch.

I think it's a little bit more nuanced - if you think of something like the Hesperia incident, where a German ship breached a japanese quarantine (1897), or e.g. the introduction of spanish flu to Samoa - you can see it doesn't really take a devious plot to knowingly introduce a plague to a vulnerable population. It just takes the ordinary colonial mix of racism, callousness, and utter disregard for human life.

There are also things like the australian smallpox epedemic, which is a little suspect, given that australia is isolated enough that the incubation and recovery period is greater than the time it takes to travel there. Obviously, people doing stuff like this don't tend to leave a load of written records, but I think it's consistent with the mentality and capabilities of people at the time to engage in purposeful biological warfare.

This is an interesting paper. There's a more "popular science" write up here:

https://theworld.org/stories/2019-01-31/european-colonizatio...

I wasn't a fan of the final line of the highlights:

> Humans contributed to Earth System changes before the Industrial Revolution

This feels like an attempt to wave a vaguely anthropogenic climate change denialist flag, not through actual denial, but "we've done stuff like this before".

What the paper calls "The Great Dying of Indigenous Peoples in the Americas" represents the death of about 10% of the total human population on the planet at the time. I'm not sure this is what you want to be comparing things to if you have the goal of in any way downplaying what fossil fuel use has done over the last 100+ years.

Of course, that may not be their intent. Even so, "two notable earth system impacts come from the death of 10% of humans worldwide and the use of fossil fuels" doesn't strike me as in any way encouraging.

> but "we've done stuff like this before".

But we have. Holocene extinction started thousands of years ago. That's not a controversial thing at all.

It’s still debatable how much of the early Holocene extinction was anthropogenic and how much was climate change or even predation. At least in terms of the megafauna like wooly mammoths and New World horses. Once state-organized civilization kicks off, consensus is that it was largely anthropogenic, even if it’s just us transporting diseases and pests around.

> or even predation

That falls under "anthropogenic", too. Humans tend to eat stuff a lot.

I think the paper wants to make a distinction between affecting "earth systems" and human instigated ecosystem transformations such as the Holocene extinction.

Whatever "earth systems" means to you will be definitely affected by massive ecosystem changes as well.

>> Humans contributed to Earth System changes before the Industrial Revolution

> This feels like an attempt to wave a vaguely anthropogenic climate change denialist flag, not through actual denial, but "we've done stuff like this before".

I think you're reading too much into this. My interpretation is just that they are pointing out a deviation from the general consensus.

> "we've done stuff like this before".

Yes, if the science says so. Yes, but the question is: Do we want to do stuff like that again?

Human impact of American colonialization: 56 million deaths.

This seems like a large-scale trolley problem. Colonization of the Americas represents throwing the lever from one track/timeline to another. Both timelines involve massive numbers of deaths that would occur earlier than on the other one. Both involve massive numbers of specific lives that existed which wouldn’t otherwise have.

Who would have died if Europeans had not colonized the Americas?

It’s impossible to say, but it seems likely that the colonial efforts of the Britain, Dutch, Spanish, and Italians would have been directed elsewhere rather than vanishing, resulting in deaths over there instead of over here. I have to think that everything that was first invented/discovered in the Americas would have eventually been invented/discovered elsewhere, but for whatever the delay in time was, people would have suffered/died in some cases. Later, possibly a lot more European Jews in the 40s. It’s an alternative timeline with a corresponding alternative set of deaths.

Not colonization, exploration. The damage was already done by the time the colonizers arrived.

The word "want" might be imprecise here.

The Spanish conquistadors were fairly brutal, but they probably did not want to exterminate the population of the entire New World outright through introduction of dangerous diseases. If only because they needed some slaves and servants for their luxurious lifestyle, plus women for their physical needs.

But in the 1500s, our understanding of contagious diseases was basically nonexistent and the first rational means of combating them (such as quarantine) were considered on par with prayers, holy processions and a judicial search for witches that might have caused the latest epidemic through deals with the Devil.

We might be doing something similar again, and again out of ignorance.

Wikipeda says that quarantine in medieval Europe had begun in the 1300s and gained it's name in Italy in about 1448. There's no evidence that it was seen as religious or mysterious, even if people then did not have a germ theory of disease.

The real issue is the people in the late 1400s and early 1500s did not appear to have any conception of widespread, genetic and experiential immunity to diseases spread directly between humans. The diseases that killed so much of the the indigenous population of the Americas really didn't have much impact on Europeans (for reasons that appear to combine both genetic ancestry and living conditions that had help force immunity long before). So the early missionaries and explorers likely did not really have a clear notion that they could be bring death to tens of millions of people, because that was basically impossible in their homelands.

"There's no evidence that it was seen as religious or mysterious"

That is not what I meant. I meant that for combatting diseases, religion and magic was used as often as things like quarantine and few people would try to hash out what was more efficient and what less.

If this is the case the Mongols and the Black Death should have similar effects in their day with the level of destruction they caused.

Neither event you mention led to land being reclaimed by nature/regrown into forests/habitats, which allegedly is how the CO2 got recaptured in this theory

Regarding the Black Death:

https://sci-hub.se/https://www.sciencedirect.com/science/art...

The tl;dr is that the forest regrowth appeared to contribute to an ongoing carbon sink event.

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