Combines multiple methods estimating pre-Columbian population numbers.
Estimates European arrival in 1492 lead to 56 million deaths by 1600.
Large population reduction led to reforestation of 55.8 Mha and 7.4 Pg C uptake.
1610 atmospheric CO2 drop partly caused by indigenous depopulation of the Americas.
Humans contributed to Earth System changes before the Industrial Revolution.
Abstract
Human impacts prior to the Industrial Revolution are not well constrained. We investigate whether the 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, were generated by natural forcing or were a result of the large-scale depopulation of the Americas after European arrival, subsequent land use change and secondary succession.
We quantitatively review the evidence for (i) the pre-Columbian population size, (ii) their per capita land use, (iii) the post-1492 population loss, (iv) the resulting carbon uptake of the abandoned anthropogenic landscapes, and then compare these to potential natural drivers of global carbon declines of 7–10 ppm. From 119 published regional population estimates we calculate a pre-1492 CE population of 60.5 million (interquartile range, IQR 44.8–78.2 million), utilizing 1.04 ha land per capita (IQR 0.98–1.11).
European epidemics removed 90% (IQR 87–92%) of the indigenous population over the next century. This resulted in secondary succession of 55.8 Mha (IQR 39.0–78.4 Mha) of abandoned land, sequestering 7.4 Pg C (IQR 4.9–10.8 Pg C), equivalent to a decline in atmospheric CO2 of 3.5 ppm (IQR 2.3–5.1 ppm CO2). Accounting for carbon cycle feedbacks plus LUC outside the Americas gives a total 5 ppm CO2 additional uptake into the land surface in the 1500s compared to the 1400s, 47–67% of the atmospheric CO2 decline.
Furthermore, we show that the global carbon budget of the 1500s cannot be balanced until large-scale vegetation regeneration in the Americas is included. The Great Dying of the Indigenous Peoples of the Americas resulted in a human-driven global impact on the Earth System in the two centuries prior to the Industrial Revolution.
Fig. 1. Global atmospheric CO2 time series. (A) The CO2 concentrations recorded in two Antarctic ice cores: Law Dome (grey, MacFarling Meure et al., 2006) and West Antarctic Ice Sheet (WAIS) Divide (blue, Ahn et al., 2012). (B) Carbon isotopic ratios recorded in CO2 from the WAIS Divide ice core (black, Bauska et al., 2015) showing an increased terrestrial carbon uptake over the 16th century (B). Yellow box is the span of the major indigenous depopulation event (1520–1700 CE). Loess smoothed lines for visual aid. Error bars are the 1-σ standard deviation. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)
8. Conclusion
We estimate that 55 million indigenous people died following the European conquest of the Americas beginning in 1492. This led to the abandonment and secondary succession of 56 million hectares of land. We calculate that this led to an additional 7.4 Pg C being removed from the atmosphere and stored on the land surface in the 1500s. This was a change from the 1400s of 9.9 Pg C (5 ppm CO2).
Including feedback processes this contributed between 47% and 67% of the 15–22 Pg C (7–10 ppm CO2) decline in atmospheric CO2 between 1520 CE and 1610 CE seen in Antarctic ice core records. These changes show that the Great Dying of the Indigenous Peoples of the Americas is necessary for a parsimonious explanation of the anomalous decrease in atmospheric CO2 at that time and the resulting decline in global surface air temperatures.
These changes show that human actions had global impacts on the Earth system in the centuries prior to the Industrial Revolution. Our results also show that this aspect of the Columbian Exchange – the globalisation of diseases – had global impacts on the Earth system, key evidence in the calls for the drop in atmospheric CO2 at 1610 CE to mark the onset of the Anthropocene epoch (Lewis and Maslin, 2015, 2018).
We conclude that the Great Dying of the Indigenous Peoples of the Americas led to the abandonment of enough cleared land in the Americas that the resulting terrestrial carbon uptake had a detectable impact on both atmospheric CO2 and global surface air temperatures in the two centuries prior to the Industrial Revolution.
The anti-colonial narrative has been part of the green mantra for some time. This is a clear example where science is being twisted to suit the narrative.
Ferdberple
February 3, 2019 12:09 am
The authors estimate that the loss of 55 million people over 100 years reduced co2 by 5ppm.
Over the past 100 years population has increased by 5.5 billion. This is 100 times greater than the 55 million population loss. By the authors reasoning this should have resulted in an increase in co2 of 500ppm without burning any fossil fuels.
However the increase in co2 was considerably less than 500ppm. This suggests that burning fossil fuels actually reduced atmospheric co2 by reducing the amount of land required to feed the population.
That in point of fact, we may not be able to reduce co2 by reducing fossil fuels if in the process we increase land use. This points to a potential problem with increased land use for renewables and biofuels.
Ferdberple
February 3, 2019 12:27 am
The reduction in co2 as a result of fossil fuel use is an idea that has not been explored. Instead the assumption is that fossil fuels increase co2, based on what would appear to be common sense.
However the co2 flux due to vegetation is very much greater than that due to fossil fuels. The assumption is that the vegetation flux nets out to zero. But the authors of this article provide evidence that this is a false assumption if population is changing.
By using fossil fuels we have dramatically decreased the amount of land required to support one human being. This should have significantly uncreased the amount if carbon stored in vegetation as compared to what would be required to support 7 billion humans without fossils fuels.
This us the point that has been overlooked. Fossil fuels increase co2 but they reduce land use which reduces co2.
Based on the authors numbers it would appear that atmospheric co2 today would be about 700ppm without using fossil fuels to support 7 billion people and about 400ppm to using fossil fuels to support 7 billion people.
I actually think the idea has merit. We have dramatically reduced the land required to support 1 human being by the use of fossil fuel which has dramatically changed the natural carbon flux IN COMPARISON to what it would take to support 7 billion otherwise. This has not been accounted for anywhere I have seen.
Ferdberple
I like your line of reasoning. However, something that needs to be taken into account is that only about half of the reasonably well-known anthropogenic CO2 shows up in the atmosphere. There are poorly known sinks that are buffering the increase in concentration.
Keith Rowe
February 3, 2019 12:32 am
My thoughts are a reduction of the H20 that the irrigation of crops from the civilizations that high population areas were decimated. The rivers of H20 we use in irrigation reduced the H20 in the air and the greatest warming factor went down. 8,000 years ago we started changing the climate. How? Irrigation.
Wasn’t it about then – 7500 years ago [or BC??] – that the Euxine, the Black Sea was formed?
That increased the area of free water available globally; would that increase be greater than that from irrigation? My guess is yes.
It also sparked various ‘Flood’ narratives, presumably including the “Noah’s Flood” one in the Old Testament.
The indigenous ancestors released a lot of CO2 burning to clear for planting & more open access to hunt animals. Gaia’s microbials then claimed sacrificial indigenous humans to reduce CO2 emissions for Gaia.
But white privilege exhaling CO2 took over & in doing so they brought about more C3 plant productivity. My inter-sectional university class made me aware how unequal this is &, I hate to tell you, that obviously Gaia is racist.
Tony Garcia
February 3, 2019 1:04 am
The unmentioned issue that I see is that there likely was contact between Europe and America prior to Colombus, and I am not using the Dighton stone here as proof, or any supposed anomalous finds; Columbus’ diary of his first voyage mentions seeing a ship hulk of European origin beached on an island, thus europeans had probably reached the American side of the Atlantic before Columbus. This injects a large amount of uncertainty into the equation.
I have and read Robert Fuson’s translation of the Log of Christopher Columbus and don’t see any evidence based on a cursory examination. There were rumors that ships had come elsewhere to the west, Columbus attributed them to the “Great Kahn.” Natives had canoes that he said would hold 40-50. Currents could have brought wreckage. Bunch of large trees just appeared on S Padre Island, origin questionable.
I worked a little with several good historians. Climate people don’t know what they are getting into. History is about as hard as it gets, Chamber of Commerce and other forms of corruption, no replication, only one history. Wait until they get into the expeditions that dealt with floods, hurricanes, etc. No way to compare it statistically.
I would check Samuel Eliot Morison’s work. He was a skeptic.
In the 1400s there was a Chinese treasure fleet commanded by Zheng He which travelled great distances.
Apparently the Chinese emperor had the fleet destroyed by the 1500s as he was afraid of foreign influences on China.
Google Zheng He to get details.
I picked this up from an article read some time ago, which I did not fact check. When I read your question, I downloaded an abbreviated copy of his journal off this site: https://archive.org/details/cihm_05312/page/n3 and read the journal. On page 219 mention is made of the firing of a lombard at a beached ship. This is the only reference I could find that may be relevant, and there is an article by an historian that claims the ship was the Santa Maria itself
(https://www.maritime-executive.com/article/Historian-Claims-Shipwreck-is-Not-Columbuss-Santa-Maria-2014-06-09), in which case it will not be another nation’s exploration vessel. Regards, Tony
In addition, I believe the island has been identified and the local settlement found, but they are still searching for the location of the spanish fort. Surprisingly, I have not yet read about anyone trying to find that ship’s ballast pile. I have read that in some cases the type of rocks used can help identify the ship’s origin….
Dave Freer
February 3, 2019 1:38 am
So… according to this Columbus prevented global warming and if not for the colonization of the Americas the world would a lot hotter. :-/
Stephen Wilde
February 3, 2019 1:39 am
Of course the corollary is that the growth of populations in North America caused the Mediaeval Warm Period.
Those wicked Red Indians.
And how do we explain the Minoan and the Holocene Optimum?
E J Zuiderwijk
February 3, 2019 1:42 am
If the demise of, for the sake of argument, 50 million and the ensuing ‘reforestation’ can make the global temperature drop by more than a degree, should not the post industrial population explosion to 5000 million have risen the temperature by some, eh, 100 degrees? (Or at least something similarly big?)
The only positive aspect of the paper is that the authors implicitly acknowledge that the little ice age was a global phenomenon.
Steve Keohane
February 3, 2019 2:35 am
They are a few thousand years late for arrival of Europeans. The copper for the bronze age probably came from the Great Lakes region. See America B.C. by Barry Fell.
saveenergy
“Corn?” Please explain. Corn (maize) was introduced to Europe in post-Columbian times, not pre-Roman. Did you mean the mineral resources of Cornwall?
Corn in english means grain, prior to the roman invasion of Britain grain (mostly wheat) was major export to the continent along with tin and copper. Corn meaning maize is american usage.
“John Barleycorn” is an old song. We’re told men came out of the west “& made a solem vow, John Barleycorn must die ….”
My impression is that originally the grain refered to as “corn” was barley. Asude from beer suitability in early agriculture barley would likely have been a more reliable crop than wheat.
Saxon word “barton” is described in an 1857 dictionary as: “… a corn town, or barley village.” England had 30 villages named Barton & some parishes too.
Barton was the name for a place around a “Bere turn”, which was a barley enclosure. Turn was derived from “tun”, which originally meant an enclosed homestead; & “ton” became an alternate pronunciation of “tun”.
Thus “Bere” was a name for barley & “Bere tun” –> “Bere ton” –>”Bere turn” –> “Barton.” I surmise the famous beer brewing site of “Burton, Trent” is another intonation of barton.
Burton’s mineral ratio in it’s water is famous for producing “crisper” tasting local beer with “body”. Now brewing supply companies offer a recreation of that local water by selling “Burton Brewing Salts” (Ca++ 352 ppm, Mg++ 45 ppm, Na+ 44 ppm (contributes to “body”),Cl 16 ppm, SO4– 801 to 820 ppm (contributes crispness & bittering) & -HCO3- 320 ppm).
I buy “Burton Brewing Salts” to put in my reverse osmosis water & carbonate for drinking; the total dissolved solids produce a tasty mineral water. I add between 1.2 to 1.6 gram per liter & carbonate that from a 20 pound CO2 tank with a regulator (using clever “Fizz Gizz” products for injection). When my rig bleeds CO2 into the air I accept the loss & am content knowing it’s plant food.
” We investigate whether the 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, were generated by natural forcing or were a result of the large-scale depopulation of the Americas after European arrival, subsequent land use change and secondary succession”
Okay, assume 10 parts per million, from 280 ppm to 270 ppm.
According to the IPCC figures, that would result in a wattage drop of
5.35 ln (270/280)= .195 watts
resulting in a temperature drop to
((240-.195)/240)*0.25 =.999797
Assume the earth was at a pleasant 14 C = 287 K BEFORE the evil Europeans wiped out the American aborigines.
Then, temperatures would have dropped to 287 K*.99979= 286.94, a horrendous drop of 0.06 C, aggravating the little ice age.
And that’s if ALL of the wattage decrease went into temperature, none into latent heat or convection loss.
Oh yea, I forgot the POSITIVE feedback, tripling the effect of a CO2 drop, which made the world a frozen ball of ice, killing all potential life 1 billion years ago.
horrendous drop of 0.06 C,
=========
And the 100 times greater population increase over the past 100 years would have increased temps 6.0 C except for fossil fuels making it possible to grow 10 times as much food per acre. As a result temps only went up 0.6 C.
AWM
February 3, 2019 5:07 am
This “passes” for “science?”
Population reduction, that’s the goal.
And starvation is very effective.
“If the reduction in CO2 caused the Little Ice Age, then why do the greenies want to reduce CO2? To put us back into another Little Ice Age?”
Well, Yes.
Yes, they do.
And the necessary reduction of population that that temperature drop would entail [without fossil fuels] – a feature of their plan, not a bug.
Their aim is a global population under 750 million; current global population about 7,681 million – ref http://www.worldometers.info/world-population/#top20@ur momisugly about 2125Z/3rd February 2019.
I have an idea. Why don’t we require all renewable energy companies donate their land and profits to Native American tribes in order to provide recompense for all the genocide and land stealing that white Europeans did. /sarc
If one looks at the combined CO2 and δ13C graph, δ13C drops and then increases first and when that stops, CO2 starts to decline. If the CO2 drop was caused by plant growth, both δ13C and CO2 would synchronize in opposite directions. δ13C and CO2 levels are measured in the same gas samples, that is not a sampling error.
Second, if one looks at the temperature reconstructions (as far as reliable), the cooling was 50-100 years before the 6 ppmv drop in the Law Dome ice core (which has a high resolution of ~20 years).
Third, there is no explanation for the initial δ13C drop before the δ13C increase. A δ13C drop is only possible by burning a large amount of organics (forests?) with adjacent regrowth and δ13C increase, but there is no increase of CO2 while δ13C drops. The only explanation I can imagine (just speculation) is that the cooling already has started while forests were burning, thus compensating for the CO2 loss, until the forests started to regrow.
Fourth, the net effect of a change of 6 ppmv in the atmosphere is good for 0.02ºC (Modtran). Not measurable in temperature or climate…
observa
February 3, 2019 6:46 am
Sounds like just another plug for Soylent Green to save Gaia unless they’re suggesting white guys aren’t generating enough diseases to do the job. Blame modern medicine I suppose.
I’ve given up trying to work out where these bizarro cult people are coming from so wild speculation it is if that’s the only game in town. The world definitely needs more flippancy.
Tom in Florida
February 3, 2019 6:58 am
While we are at it, let’s not forget to blame modern humans for exterminating the Neanderthals.
Johann Wundersamer
February 3, 2019 7:08 am
globally lowered surface air temperatures by 0.15∘C, were generated by natural forcing or were a result of the large-scale depopulation of the Americas after European arrival, subsequent land use change and secondary succession.
population estimates we calculate a pre-1492 CE population of 60.5 million.
___________________________________________________
No revision of history is needed, the devastating effect of the epidemics is well documented in contemporary sources. One example from a Franciscan friar:
“Nobody had the health or strength to help the diseased or bury the dead. In the cities and large towns, big ditches were dug, and from morning to sunset the priests did nothing else but carry the dead bodies and throw them into the ditches.”
Phil,
Who dug the “big ditches?” That is probably even harder work than loading bodies onto a wagon. Are we to believe that a couple friars buried 90% of a town?
They wrote, “…this contributed between 47% and 67% of the 15–22 Pg C (7–10 ppm CO2) decline in atmospheric CO2 between 1520 CE and 1610 CE seen in Antarctic ice core records.”
That “75-year smoothed” ice core data does show a 7.6 ppmv decline in CO2 level from 1520 to 1610 AD. Here’s an excerpt:
You can see that the decline started about 1545 AD. That corresponds nicely with the worst of the Aztec epidemics:
However, it is about two centuries too late to have caused the Little Ice Age. By 1545 the Viking settlers had already been frozen out of Greenland for a century or more. Here’s a graph from the FAR:
What’s more, the truth is that nobody really knows the cause of what these authors call the “European epidemics” that devastated native Aztec and Inca populations. Here’s an article. (Ignore the idiotic headline, which is contradicted by the article; most newspapers add their own headlines, which are frequently inaccurate.)
That 7.6 ppmv drop in CO2 level from 1520 AD (283.1) to 1610 AD (275.5) represents a 2.7% decline (if it is real, and not just an artifact of imprecise ice core measurements).
If TCR sensitivity is 1°C/doubling (my estimate), then that 2.7% change in CO2 level corresponds to a temperature difference of log2(283.1/275.5) = 0.0393°C.
if TCR sensitivity is 2°C/doubling (a typical IPCC/alarmist estimate), then that 2.7% change in CO2 level corresponds to a temperature difference of 2×log2(283.1/275.5) = 0.0785°C.
That includes the effects of all short-term feedbacks.
I wonder is how drek like this makes it through peer-review? It seems that climate science has become one of those fields, like “gender studies” and “critical race theory,” which are dominated by crackpots. Much of the the drek that passes “peer-review,” and gets published in high-profile academic journals, is comparable to this:
Colder water absorbs more CO2, so I’d expect CO2 levels to drop due to the temperature change of the Little Ice Age.
CO2 levels were around 200 ppm during the last glacial maximum vs. the normal pre-industrial 280ppm, and I believe it was about 8°C colder, so that’s roughly 10ppm per degree.
If the Little Ice Age temperature drop was around 1°C, that’s in the ballpark of the 7.6 ppm drop you found.
I agree, Bart, and that also constitutes evidence that the MWP-to-LIA cooling was global, rather than merely regional.
There’s a big ongoing debate about that. Defenders of the Mann/Jones/et al “hockey stick” need for the warm MWP and cool LIA to have been merely regional. But if the MWP & LIA were merely regional (Europe & Greenland), rather than global, then they couldn’t have caused much change in CO2 levels in Antarctica (the site of this ice core record).
The IPCC in AR5 acknowledges the LIA was global, affecting both the Northern and Southern Hemispheres. They are fuzzy about the MWP, indicating there is debate about it.
Do the global-MWP-deniers have any explanation for the law dome CO2 increase during the MWP?
Those idiotic claims on human caused climate disruptions seem to be endless.
Here is another climate fool who claims that humans began to modify the climate 5000 years ago, disrupting Milankovitch cycles with methane (breeding) and after, CO2 emission :
The anti-colonial narrative has been part of the green mantra for some time. This is a clear example where science is being twisted to suit the narrative.
The authors estimate that the loss of 55 million people over 100 years reduced co2 by 5ppm.
Over the past 100 years population has increased by 5.5 billion. This is 100 times greater than the 55 million population loss. By the authors reasoning this should have resulted in an increase in co2 of 500ppm without burning any fossil fuels.
However the increase in co2 was considerably less than 500ppm. This suggests that burning fossil fuels actually reduced atmospheric co2 by reducing the amount of land required to feed the population.
That in point of fact, we may not be able to reduce co2 by reducing fossil fuels if in the process we increase land use. This points to a potential problem with increased land use for renewables and biofuels.
The reduction in co2 as a result of fossil fuel use is an idea that has not been explored. Instead the assumption is that fossil fuels increase co2, based on what would appear to be common sense.
However the co2 flux due to vegetation is very much greater than that due to fossil fuels. The assumption is that the vegetation flux nets out to zero. But the authors of this article provide evidence that this is a false assumption if population is changing.
By using fossil fuels we have dramatically decreased the amount of land required to support one human being. This should have significantly uncreased the amount if carbon stored in vegetation as compared to what would be required to support 7 billion humans without fossils fuels.
This us the point that has been overlooked. Fossil fuels increase co2 but they reduce land use which reduces co2.
Based on the authors numbers it would appear that atmospheric co2 today would be about 700ppm without using fossil fuels to support 7 billion people and about 400ppm to using fossil fuels to support 7 billion people.
Brilliant.
Grant request to follow?
I’m still waiting on my first check from big oil.
I actually think the idea has merit. We have dramatically reduced the land required to support 1 human being by the use of fossil fuel which has dramatically changed the natural carbon flux IN COMPARISON to what it would take to support 7 billion otherwise. This has not been accounted for anywhere I have seen.
Ferdberple
I like your line of reasoning. However, something that needs to be taken into account is that only about half of the reasonably well-known anthropogenic CO2 shows up in the atmosphere. There are poorly known sinks that are buffering the increase in concentration.
My thoughts are a reduction of the H20 that the irrigation of crops from the civilizations that high population areas were decimated. The rivers of H20 we use in irrigation reduced the H20 in the air and the greatest warming factor went down. 8,000 years ago we started changing the climate. How? Irrigation.
Wasn’t it about then – 7500 years ago [or BC??] – that the Euxine, the Black Sea was formed?
That increased the area of free water available globally; would that increase be greater than that from irrigation? My guess is yes.
It also sparked various ‘Flood’ narratives, presumably including the “Noah’s Flood” one in the Old Testament.
Auto
The indigenous ancestors released a lot of CO2 burning to clear for planting & more open access to hunt animals. Gaia’s microbials then claimed sacrificial indigenous humans to reduce CO2 emissions for Gaia.
But white privilege exhaling CO2 took over & in doing so they brought about more C3 plant productivity. My inter-sectional university class made me aware how unequal this is &, I hate to tell you, that obviously Gaia is racist.
The unmentioned issue that I see is that there likely was contact between Europe and America prior to Colombus, and I am not using the Dighton stone here as proof, or any supposed anomalous finds; Columbus’ diary of his first voyage mentions seeing a ship hulk of European origin beached on an island, thus europeans had probably reached the American side of the Atlantic before Columbus. This injects a large amount of uncertainty into the equation.
Tony Garcia,
Do you have a reference for:
‘Columbus’ diary of his first voyage mentions seeing a ship hulk of European origin beached on an island’?
A quick Google didn’t come up with anything.
Ciao
John
I have and read Robert Fuson’s translation of the Log of Christopher Columbus and don’t see any evidence based on a cursory examination. There were rumors that ships had come elsewhere to the west, Columbus attributed them to the “Great Kahn.” Natives had canoes that he said would hold 40-50. Currents could have brought wreckage. Bunch of large trees just appeared on S Padre Island, origin questionable.
I worked a little with several good historians. Climate people don’t know what they are getting into. History is about as hard as it gets, Chamber of Commerce and other forms of corruption, no replication, only one history. Wait until they get into the expeditions that dealt with floods, hurricanes, etc. No way to compare it statistically.
I would check Samuel Eliot Morison’s work. He was a skeptic.
In the 1400s there was a Chinese treasure fleet commanded by Zheng He which travelled great distances.
Apparently the Chinese emperor had the fleet destroyed by the 1500s as he was afraid of foreign influences on China.
Google Zheng He to get details.
Did they also travel in the Atlantic? I’ve only read about their travels in the Pacific.
I picked this up from an article read some time ago, which I did not fact check. When I read your question, I downloaded an abbreviated copy of his journal off this site: https://archive.org/details/cihm_05312/page/n3 and read the journal. On page 219 mention is made of the firing of a lombard at a beached ship. This is the only reference I could find that may be relevant, and there is an article by an historian that claims the ship was the Santa Maria itself
(https://www.maritime-executive.com/article/Historian-Claims-Shipwreck-is-Not-Columbuss-Santa-Maria-2014-06-09), in which case it will not be another nation’s exploration vessel. Regards, Tony
In addition, I believe the island has been identified and the local settlement found, but they are still searching for the location of the spanish fort. Surprisingly, I have not yet read about anyone trying to find that ship’s ballast pile. I have read that in some cases the type of rocks used can help identify the ship’s origin….
So… according to this Columbus prevented global warming and if not for the colonization of the Americas the world would a lot hotter. :-/
Of course the corollary is that the growth of populations in North America caused the Mediaeval Warm Period.
Those wicked Red Indians.
And how do we explain the Minoan and the Holocene Optimum?
If the demise of, for the sake of argument, 50 million and the ensuing ‘reforestation’ can make the global temperature drop by more than a degree, should not the post industrial population explosion to 5000 million have risen the temperature by some, eh, 100 degrees? (Or at least something similarly big?)
The only positive aspect of the paper is that the authors implicitly acknowledge that the little ice age was a global phenomenon.
They are a few thousand years late for arrival of Europeans. The copper for the bronze age probably came from the Great Lakes region. See America B.C. by Barry Fell.
There is a big island in the Mediterranean called Cyprus, which gave its name to the metal found there in abundance, Cuprum, copper.
The Phoenicians got everywhere –
The Great Orme copper mine was estimated to have produced enough copper to make about 2,000 tons of bronze during the Bronze Age.
https://www.atlasobscura.com/places/the-great-orme-copper-mines-conwy-wales
&
https://en.wikipedia.org/wiki/Parys_Mountain
&
1,000yrs later – http://www.cornwall-calling.co.uk/mines.htm
Copper, Tin & corn were the main reasons for Rome invading Britain.
saveenergy
“Corn?” Please explain. Corn (maize) was introduced to Europe in post-Columbian times, not pre-Roman. Did you mean the mineral resources of Cornwall?
In England “corn” means wheat.
Guessing they mean “coal” instead of “corn”. Just a guess.
Corn in english means grain, prior to the roman invasion of Britain grain (mostly wheat) was major export to the continent along with tin and copper. Corn meaning maize is american usage.
“John Barleycorn” is an old song. We’re told men came out of the west “& made a solem vow, John Barleycorn must die ….”
My impression is that originally the grain refered to as “corn” was barley. Asude from beer suitability in early agriculture barley would likely have been a more reliable crop than wheat.
Saxon word “barton” is described in an 1857 dictionary as: “… a corn town, or barley village.” England had 30 villages named Barton & some parishes too.
Barton was the name for a place around a “Bere turn”, which was a barley enclosure. Turn was derived from “tun”, which originally meant an enclosed homestead; & “ton” became an alternate pronunciation of “tun”.
Thus “Bere” was a name for barley & “Bere tun” –> “Bere ton” –>”Bere turn” –> “Barton.” I surmise the famous beer brewing site of “Burton, Trent” is another intonation of barton.
Burton’s mineral ratio in it’s water is famous for producing “crisper” tasting local beer with “body”. Now brewing supply companies offer a recreation of that local water by selling “Burton Brewing Salts” (Ca++ 352 ppm, Mg++ 45 ppm, Na+ 44 ppm (contributes to “body”),Cl 16 ppm, SO4– 801 to 820 ppm (contributes crispness & bittering) & -HCO3- 320 ppm).
I buy “Burton Brewing Salts” to put in my reverse osmosis water & carbonate for drinking; the total dissolved solids produce a tasty mineral water. I add between 1.2 to 1.6 gram per liter & carbonate that from a 20 pound CO2 tank with a regulator (using clever “Fizz Gizz” products for injection). When my rig bleeds CO2 into the air I accept the loss & am content knowing it’s plant food.
Thank you for that fascinating info, gringojay!
Here’s the song:
https://www.youtube.com/watch?v=fsIdhSzyx8M
These folks have a slightly different version of the story about the origin of the names:
http://www.surnamedb.com/Surname/Barton
http://www.surnamedb.com/Surname/Burton
I kind of like your version. 😀
” We investigate whether the 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, were generated by natural forcing or were a result of the large-scale depopulation of the Americas after European arrival, subsequent land use change and secondary succession”
Okay, assume 10 parts per million, from 280 ppm to 270 ppm.
According to the IPCC figures, that would result in a wattage drop of
5.35 ln (270/280)= .195 watts
resulting in a temperature drop to
((240-.195)/240)*0.25 =.999797
Assume the earth was at a pleasant 14 C = 287 K BEFORE the evil Europeans wiped out the American aborigines.
Then, temperatures would have dropped to 287 K*.99979= 286.94, a horrendous drop of 0.06 C, aggravating the little ice age.
And that’s if ALL of the wattage decrease went into temperature, none into latent heat or convection loss.
Oh yea, I forgot the POSITIVE feedback, tripling the effect of a CO2 drop, which made the world a frozen ball of ice, killing all potential life 1 billion years ago.
http://clivebest.com/blog/?p=3659
horrendous drop of 0.06 C,
=========
And the 100 times greater population increase over the past 100 years would have increased temps 6.0 C except for fossil fuels making it possible to grow 10 times as much food per acre. As a result temps only went up 0.6 C.
This “passes” for “science?”
Population reduction, that’s the goal.
And starvation is very effective.
If the reduction in CO2 caused the Little Ice Age, then why do the greenies want to reduce CO2? To put us back into another Little Ice Age?
StephenP
February 3, 2019 at 5:25 am
“If the reduction in CO2 caused the Little Ice Age, then why do the greenies want to reduce CO2? To put us back into another Little Ice Age?”
Well, Yes.
Yes, they do.
And the necessary reduction of population that that temperature drop would entail [without fossil fuels] – a feature of their plan, not a bug.
Their aim is a global population under 750 million; current global population about 7,681 million – ref http://www.worldometers.info/world-population/#top20 @ur momisugly about 2125Z/3rd February 2019.
Auto
I have an idea. Why don’t we require all renewable energy companies donate their land and profits to Native American tribes in order to provide recompense for all the genocide and land stealing that white Europeans did. /sarc
The timing of these events doesn’t synchronize…
If one looks at the combined CO2 and δ13C graph, δ13C drops and then increases first and when that stops, CO2 starts to decline. If the CO2 drop was caused by plant growth, both δ13C and CO2 would synchronize in opposite directions. δ13C and CO2 levels are measured in the same gas samples, that is not a sampling error.
Second, if one looks at the temperature reconstructions (as far as reliable), the cooling was 50-100 years before the 6 ppmv drop in the Law Dome ice core (which has a high resolution of ~20 years).
Third, there is no explanation for the initial δ13C drop before the δ13C increase. A δ13C drop is only possible by burning a large amount of organics (forests?) with adjacent regrowth and δ13C increase, but there is no increase of CO2 while δ13C drops. The only explanation I can imagine (just speculation) is that the cooling already has started while forests were burning, thus compensating for the CO2 loss, until the forests started to regrow.
Fourth, the net effect of a change of 6 ppmv in the atmosphere is good for 0.02ºC (Modtran). Not measurable in temperature or climate…
Sounds like just another plug for Soylent Green to save Gaia unless they’re suggesting white guys aren’t generating enough diseases to do the job. Blame modern medicine I suppose.
I’ve given up trying to work out where these bizarro cult people are coming from so wild speculation it is if that’s the only game in town. The world definitely needs more flippancy.
While we are at it, let’s not forget to blame modern humans for exterminating the Neanderthals.
globally lowered surface air temperatures by 0.15∘C, were generated by natural forcing or were a result of the large-scale depopulation of the Americas after European arrival, subsequent land use change and secondary succession.
population estimates we calculate a pre-1492 CE population of 60.5 million.
___________________________________________________
Now there’s https://www.google.com/search?q=latin+america+population+2100&oq=Latin+america+populations&aqs=chrome. and we’re brave waiting for doomsday.
Ah… Those evil Europeans destroyed Wakanda in the Americas with their magic CO2 molecule and disease, ‘eh?
The Socialists revising history again and pretending that the science proves it.
No revision of history is needed, the devastating effect of the epidemics is well documented in contemporary sources. One example from a Franciscan friar:
“Nobody had the health or strength to help the diseased or bury the dead. In the cities and large towns, big ditches were dug, and from morning to sunset the priests did nothing else but carry the dead bodies and throw them into the ditches.”
Phil,
Who dug the “big ditches?” That is probably even harder work than loading bodies onto a wagon. Are we to believe that a couple friars buried 90% of a town?
This might be the CO2 record that has them all in a tizzy:
https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/law/law_co2.txt
They wrote, “…this contributed between 47% and 67% of the 15–22 Pg C (7–10 ppm CO2) decline in atmospheric CO2 between 1520 CE and 1610 CE seen in Antarctic ice core records.”
That “75-year smoothed” ice core data does show a 7.6 ppmv decline in CO2 level from 1520 to 1610 AD. Here’s an excerpt:
1520 283.1
1525 283.2
1530 283.2
1535 283.2
1540 283.1
1545 283.0
1550 282.8
1555 282.6
1560 282.2
1565 281.8
1570 281.2
1575 280.5
1580 279.7
1585 278.8
1590 278.0
1595 277.1
1600 276.4
1605 275.8
1610 275.5
You can see that the decline started about 1545 AD. That corresponds nicely with the worst of the Aztec epidemics:
However, it is about two centuries too late to have caused the Little Ice Age. By 1545 the Viking settlers had already been frozen out of Greenland for a century or more. Here’s a graph from the FAR:
What’s more, the truth is that nobody really knows the cause of what these authors call the “European epidemics” that devastated native Aztec and Inca populations. Here’s an article. (Ignore the idiotic headline, which is contradicted by the article; most newspapers add their own headlines, which are frequently inaccurate.)
https://www.news.com.au/technology/science/archaeology/500-years-later-scientists-think-theyve-solved-germ-mystery-that-nearly-wiped-out-mexican-population/news-story/f35d6baab1f756cf2ae4a8b898bcfa80
That 7.6 ppmv drop in CO2 level from 1520 AD (283.1) to 1610 AD (275.5) represents a 2.7% decline (if it is real, and not just an artifact of imprecise ice core measurements).
If TCR sensitivity is 1°C/doubling (my estimate), then that 2.7% change in CO2 level corresponds to a temperature difference of log2(283.1/275.5) = 0.0393°C.
if TCR sensitivity is 2°C/doubling (a typical IPCC/alarmist estimate), then that 2.7% change in CO2 level corresponds to a temperature difference of 2×log2(283.1/275.5) = 0.0785°C.
That includes the effects of all short-term feedbacks.
Yet the authors attribute a 0.15°C change in temperature to that tiny change in CO2 level, which implies a TCR sensitivity of 3.82°C/doubling. That is much higher than the assumed TCR sensitivity baked into any of the 30 models which AR5 lists in Table 9.5:
https://sealevel.info/AR5_Table_9.5_p.818.pdf
Source:
http://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter09_FINAL.pdf#page=78
I wonder is how drek like this makes it through peer-review? It seems that climate science has become one of those fields, like “gender studies” and “critical race theory,” which are dominated by crackpots. Much of the the drek that passes “peer-review,” and gets published in high-profile academic journals, is comparable to this:
https://youtu.be/kVk9a5Jcd1k
Colder water absorbs more CO2, so I’d expect CO2 levels to drop due to the temperature change of the Little Ice Age.
CO2 levels were around 200 ppm during the last glacial maximum vs. the normal pre-industrial 280ppm, and I believe it was about 8°C colder, so that’s roughly 10ppm per degree.
If the Little Ice Age temperature drop was around 1°C, that’s in the ballpark of the 7.6 ppm drop you found.
I agree, Bart, and that also constitutes evidence that the MWP-to-LIA cooling was global, rather than merely regional.
There’s a big ongoing debate about that. Defenders of the Mann/Jones/et al “hockey stick” need for the warm MWP and cool LIA to have been merely regional. But if the MWP & LIA were merely regional (Europe & Greenland), rather than global, then they couldn’t have caused much change in CO2 levels in Antarctica (the site of this ice core record).
The IPCC in AR5 acknowledges the LIA was global, affecting both the Northern and Southern Hemispheres. They are fuzzy about the MWP, indicating there is debate about it.
Do the global-MWP-deniers have any explanation for the law dome CO2 increase during the MWP?
The oceans are usually in their warm phases during centennial solar minima, because of increased negative NAO/AO.
Those idiotic claims on human caused climate disruptions seem to be endless.
Here is another climate fool who claims that humans began to modify the climate 5000 years ago, disrupting Milankovitch cycles with methane (breeding) and after, CO2 emission :
How was this census of the population of the Western Hemisphere conducted, exactly?
Mosher must know, he defends this ludicrous waste of paper and bandwidth…
Fabricated estimates to appease the Faithful of the Caliphate.
Ha
Not sure if these contributed to the coldest part of the global Little Ice Age (hey, that’s a thing again):
https://www.foxnews.com/science/15th-century-mass-child-sacrifice-site-in-peru-may-be-linked-to-el-nino-event
Pointless, self-destructive behaviour in an effort to change the weather is nothing new.
I thought the “scientific consensus” was the little ice age was not global.