How El Niño and Drought Affected the Trans-Atlantic Slave Trade

Weather and climate intertwined with slavery and conflict, bearing lessons that reverberate today


Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA – DAVIS

Terrence Nathan and WIlliam Turner IV
IMAGE: FROM LEFT, PROFESSOR TERRENCE NATHAN AND PH.D. STUDENT WILLIAM TURNER IV OF THE UC DAVIS DEPARTMENT OF LAND, AIR AND WATER RESOURCES. view more  CREDIT: UC DAVIS

El Niño, an oceanic phenomenon that affects worldwide weather patterns, significantly affected the number of enslaved Africans transported from West Africa to the Americas between the mid-1600s and mid-1800s, according to a study from the University of California, Davis. 

The study, published in the American Meteorological Society journal Weather, Climate and Society, bridges atmospheric science with African history. It also shares lessons for today amid a warming future that threatens to exacerbate human conflict and migrations.

The study found that El Niño can be used as a proxy — much like tree rings and corals — for historical rainfall and temperature patterns in West Africa. The authors used reconstructed El Niño indices and the Slave Voyages dataset to examine the relationship between El Niño and the trans-Atlantic slave trade.

Historians have suggested, based upon qualitative assessments of journals, documents and chronicles, that droughts affected the trans-Atlantic slave trade. But they have not been able to quantify that relationship or to ascribe a mechanism for the droughts.

“The trans-Atlantic slave trade began in the 1400s, but instrumental rainfall data only goes back to around the 1800s,” said lead author William Turner IV, a Ph.D. student at UC Davis in the Department of Land, Air and Water Resources. “To fill this data gap, we relied on the proxy association between El Niño and rainfall. We found that during El Niño, West Africa experiences drier conditions.”

Delayed response

The authors found that El Niño-induced drier conditions are associated with a decrease in the number of enslaved people brought to the Americas, and it happened at a two-year lag. The lag is important, showing that El Niño-induced drier conditions caused a delayed response in the slave trade.

The authors suggest that agricultural stresses may have reduced the demand for slaves during droughts, resulting in the decrease of enslaved peoples transported from Africa. They note, however, that sociological studies are needed to fully understand how West African societies responded to drought during the slave trade. Nonetheless, they found a clear association between El Niño and the slave trade.

When ‘commodities’ are enslaved people

“What surprised me was how detailed the ship logs were,” said co-author Terrence Nathan, a professor in the UC Davis Department of Land, Air and Water Resources. “The logs documented the weather, as well as the number of enslaved individuals who left the ports and survived the tortuous journey on ships that carried as many as 700 enslaved Africans with only 3 square feet allotted to each person. The enslaved individuals were simply treated as commodities for insurance purposes, further underscoring the inhumanity of the slave trade.”  

“To acknowledge their humanity, we used the terminology ‘enslaved’ rather than ‘slave’ throughout the paper,” Turner said.

Learning from the past

“In this study, we showed that weather was one of several driving forces of the trans-Atlantic slave trade,” said Nathan. “Lessons learned from this study reverberate today, as evidenced by the Syrian civil war, which studies have shown was exacerbated by extreme drought. Given current projections of climate change, one can only wonder what the future holds for future potential conflicts when people are forced to move from hotter and drier areas.”

The authors end the study with the West African word “sankofa,” which roughly translates to “the past informs the future.”

“‘Sankofa’ means to not dwell on the past but to learn from it and understand how we got here today so we can have a better future for tomorrow,” Turner said.

The study was funded by the National Science Foundation.


JOURNAL

Weather Climate and Society

DOI

10.1175/WCAS-D-21-0036.1 

METHOD OF RESEARCH

Data/statistical analysis

ARTICLE TITLE

The El Niño–Southern Oscillation and the Transatlantic Slave Trade

ARTICLE PUBLICATION DATE

6-Dec-2021

From EurekAlert!

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Dena
February 12, 2022 6:47 pm

The link is simple. If you don’t have the crops to sell, you don’t have the money to buy additional slaves. In a good year you have the money to expand your operation. In addition, it make take a couple of years to get back on your feet but one bad year may not deplete your cash reserves. I guess they don’t teach much in economics anymore.

Mohatdebos
February 12, 2022 6:59 pm

.I am confused! Are they suggesting that El Niño resulted in drought In West Africa or are they suggesting that it resulted in drought in the Americas, which reduced demand for slaves.

Reply to  Mohatdebos
February 12, 2022 7:28 pm

Wouldn’t drought in West Africa increase the supply of slaves? The tribes capturing and selling the slaves would have an incentive to reduce the competition for scarce food, water, game, etc., and sending them offshore while collecting a bounty would seem like a win-win.

commieBob
Reply to  Mohatdebos
February 12, 2022 7:33 pm

They don’t say.

The authors suggest that agricultural stresses may have reduced the demand for slaves during droughts, resulting in the decrease of enslaved peoples transported from Africa. They note, however, that sociological studies are needed to fully understand how West African societies responded to drought during the slave trade. Nonetheless, they found a clear association between El Niño and the slave trade.

All they say is there is a correlation between El Niño and the slave trade. They don’t say why.

Given the replication crisis, the starting position should be to assume that a published research finding is wrong.

It seems obvious that one would check the records of the plantation owners and yet this isn’t mentioned. It also seems obvious that one would check the size of agricultural exports back to Europe. That would certainly be as well documented as the number of slaves being shipped and yet they didn’t mention that either. Plus they had to use proxies for the El Niños.

So, they didn’t do things that would back up their data and they relied on proxies that they probably didn’t understand all that well. Just look at what Dr. Mann, a physicist, did with tree rings. (hint … I don’t remember anything about tree rings in any of my physics courses)

If you check enough things, you will eventually get a publishable p-value. link link

Reply to  commieBob
February 12, 2022 7:45 pm

> If you check enough things, you will eventually get a publishable p-value.

Not to mention https://www.tylervigen.com/spurious-correlations

Tom Abbott
Reply to  commieBob
February 13, 2022 5:16 am

“Given the replication crisis, the starting position should be to assume that a published research finding is wrong.”

Good advice.

MarkW
Reply to  Tom Abbott
February 13, 2022 6:50 am

Even without the replication crisis, a scientist should always start with the assumption that a published research finding is wrong.

Only after you confirm their findings for yourself should you accept the paper as being valid.

George Daddis
Reply to  commieBob
February 13, 2022 7:59 am

Yes!
“….showing that El Niño-induced drier conditions caused a delayed response in the slave trade..”
Correlation is not causation.

Reply to  commieBob
February 13, 2022 11:05 am

Importing slaves into the United States was banned in 1808.
England shut down their complicity in the slave trade a few years after 1808.

Pirates freed slaves and offered them work as pirates.
Leaving Dutch, Spanish and Portuguese ships as the main slave traders.

Leaving a lot of doubt about what these characters could hypothesize regarding El Nino, rainfall and droughts in the Caribbean, Central America and South America where detailed records were very sparse.

Then there is this little note:

The first shipload of African captives to the British colonies in North America arrived at JamestownVirginia, in August 1619, but for most of the 17th century, European indentured servants were far more numerous in the North American British colonies than were enslaved Africans. However, after 1680, the flow of indentured servants sharply declined, leading to an explosion in the African slave trade.”

England enslaved various groups that engaged in revolt or sedition as the Irish and Scottish were inclined to disagree with and fight the English.

The English also supplied the bulk of slaves imported into America, most well before the American Revolution in the late 18th century.

I found one Scottish ancestor who arrived in America during the 1600s as an enslaved soldier captured after a battle. When he was granted freedom after years of productive enslavement, he chose to stay in America, settling north of Boston.

Scissor
Reply to  Mohatdebos
February 12, 2022 7:37 pm

Me too. In their Introduction, they said, “From 1440 to 1870, economic forces produced the largest forced migration in history: The Trans-Atlantic Slave Trade (TAST).”

That starting date of 1440 seems odd, predating Columbus’s first voyage by 52 years.

commieBob
Reply to  Scissor
February 12, 2022 7:59 pm

Good catch. When I was a kid,

In fourteen hundred ninetytwo. Columbus sailed the ocean blue

was engraved on the inside of my cranium.

I have very often noted PhDs who are unaware of things that are common knowledge. It would be bad enough if just one person made that error but there were co-authors and editors involved. Has our education system become that bad?

Alan the Brit
Reply to  commieBob
February 13, 2022 12:36 am

Yes I would suggest, just as it is in the UK. From experience of listening to engineering students they won’t graduate unless their final thesis contains the expression, “due to manmade Climate Change”, it’s a given!!!

RevJay4
Reply to  commieBob
February 13, 2022 4:49 am

Yep. It really has become that bad. Old Christopher Columbus was a white supremacist, doncha know?

MarkW
Reply to  RevJay4
February 13, 2022 6:55 am

It’s human nature to assume your own tribe is the best. Has been since homo sapien first figured out how to shape a rock.
But apparently it’s only a bad thing when people of European descent do it.

Reply to  MarkW
February 13, 2022 11:12 am

In Christopher Columbus’ case, he had a backup tribe.
Spain financed his trips and Italy collected some of the glory after the discovery.

2hotel9
Reply to  commieBob
February 13, 2022 8:06 am

Yes, yes it has.

Richard Page
Reply to  commieBob
February 13, 2022 8:32 am

It wasn’t an error on their part, but yours – please see my previous post for the explanation.

Reply to  Richard Page
February 13, 2022 11:13 am

please see my previous post”

A meaningless phrase unless you include a direct link.

commieBob
Reply to  Richard Page
February 14, 2022 4:58 am

Why haven’t you replied to Felix’s reply to that post?

Reply to  Scissor
February 12, 2022 8:23 pm

They’ve appear to have based that 1440 on mis-reading one paper.

http://ap.gilderlehrman.org/history-by-era/origins-slavery/essays/iberian-roots-transatlantic-slave-trade-1440%E2%80%931640

Iberian Roots of the Transatlantic Slave Trade, 1440–1640...
One recent study suggests that as many as 350,000 to 400,000 African captives may have been transported to Spain and Portugal during the two centuries from 1440 to 1640.

The first slave trade voyage known to have sailed directly from Africa to the Americas arrived in Santo Domingo, on the island Española (Hispaniola), in 1525.

Reply to  StuM
February 13, 2022 3:05 am

I have enormous doubts about the reliability of the numbers in the cited source. There is no bibliographic references in that text, I cannot check the claims that are made. There is a factual error: “moriscos” were NOT slaves. They were perhaps 5% of the population in eearly 1600s when Phillip III of Spain ordered the eviction of all moriscos (were sent to North Africa 300 or 350 thousand of a total population near 9 million). They should be the majority of the islamic (north African descent) population, settled in the Peninsula since the 8th century as free peasants. To my knowledge, the slave (forced labour, not free people, people as property of others) population in Portugal and Spain was very limited in the cited period (mid 15th to mid 17th centuries), few were employed as workers in agriculture, most were used as household “ostentation of wealth” and employed in domestic chores.

Scissor
Reply to  StuM
February 13, 2022 6:36 am

That’s informative, thanks StuM.

John Hultquist
Reply to  Scissor
February 12, 2022 8:40 pm

It’s complicated and did not start with the Americas.
Slavery and Slave Trade in West Africa, 1450-1930 
http://www.aehnetwork.org/textbook/ 

Scissor
Reply to  John Hultquist
February 13, 2022 6:39 am

I’ll attribute it to poor grammar then as trans Atlantic denotes crossing the Atlantic Ocean.

Dave Andrews
Reply to  John Hultquist
February 13, 2022 6:53 am

Plus there was the Arab Slave Trade that lasted some 1300 years and transported African slaves to Arabic countries and across the Indian Ocean.

tonyb
Editor
Reply to  Scissor
February 13, 2022 12:01 am

Slavery has unfortunately always gone on from earliest times in Mesopotamia and most nations including African ones have been complicit, at times supplying and at other times being the slaves. The Pyramids, Greater Zimbabwe the Roman Empire were all built on slavery.

The Largest slave market in the 9th Century was Dublin with white slaves. Until around 1500 or later the largest portion of the slave trade were white ones being taken to North Africa and further afield with the Barbars and Arabs being especially complicit. Around 2 million white slaves were often snatched from coastal towns in Europe including here on the south coast of England.

Congregations would attempt to buy them back. There are many accounts of slave traders and their white slaves of which the best is ‘White gold.’ Unfortunately this evil trade still goes on in various parts of the world

RevJay4
Reply to  tonyb
February 13, 2022 5:16 am

Now that is an “inconvenient truth”, as the grand poobah of climate crap so loudly proclaims and proselytizes. Only this time it is about “slavery”. With climate alarmism thrown in for good measure.
“America” is just being handed a guilt trip about something which no one alive today had any part in. Of course, the leftists have being trying that one out for the last 100+ years. Common sense 101 sez guilt belongs to the folks long since dead.

Tom Abbott
Reply to  tonyb
February 13, 2022 5:23 am

“Unfortunately this evil trade still goes on in various parts of the world”

Yes, and the United States has a president who is enabling such crimes by refusing to close the U.S. southern border to slavers, and further enables the slavers by transporting their slaves all over the United States at taxpayer expense.

MarkW
Reply to  tonyb
February 13, 2022 6:58 am

The pyramids were not built using slave labor.

Mohatdebos
Reply to  tonyb
February 13, 2022 9:10 am

The English word slave is derived from Slavic. The Viking regularly raided Slavic countries to enslave people. The Viking long boats were manned by slaves.

MarkW
Reply to  Scissor
February 13, 2022 6:53 am

Doesn’t the 1619 project claim that 1619 was the year the first slave was shipped to N. America proper?

Felix
Reply to  Scissor
February 13, 2022 7:35 am

I was suspicious of “The trans-Atlantic slave trade began in the 1400s” but hadn’t read the paper itself o see that exact phony date.

Richard Page
Reply to  Scissor
February 13, 2022 8:30 am

Only if you’re viewing the situation from a purely american-centric position. Slave shipments began around 1430-40 when Portugese ships first started bringing African slaves to Europe. The first slaves to arrive in North America would be around 1619 in Jamestown, when a Portugese slave ship was captured by English privateers and brought there.

Felix
Reply to  Richard Page
February 13, 2022 12:40 pm

What the heck do you think “trans-Atlantic” means? Either Europe or Africa on the eastern side, but the western said can only be the Americas. And that’s not “purely America-centric”, because no is dumb enough to think “trans-Atlantic” involves only the Americas.

Please explain. Your comment makes no sense.

Richard Page
Reply to  Felix
February 14, 2022 5:49 am

‘Transatlantic’ as in from one side of the Atlantic to the other, or from opposite sides of the Atlantic is only one definition of the word – it was also used to mean any crossing through part of the Atlantic, so Africa to Europe (excluding any Mediterranean crossing) was also considered ‘transatlantic’ if the ships sailed into the Atlantic Ocean. Actually my initial post was about the slave trade predating the discovery of the America’s, not the issue of the definition of ‘transatlantic’.

Peter Fraser
Reply to  Mohatdebos
February 13, 2022 10:19 am

Take your pick. Both are long bows.

markl
February 12, 2022 7:29 pm

Doh.

Farmer Ch E retired
Reply to  markl
February 13, 2022 6:32 am

Double Doh – “sankofa,” which roughly translates to “the past informs the future.”
In the 21st century, do we now have a Trans-Pacific slave trade? The present-day slaves get to stay and work in their totalitarian countries and its the products of their labor that are transported in container ships around the globe. Which US state has the largest stake in the 21st century Trans-Pacific slave trade?

Richard Page
Reply to  Farmer Ch E retired
February 14, 2022 5:54 am

There’s also a trans-European slave trade with many being trafficked from poorer countries in Eastern Europe, Balkans and others, often for sex work. It is what it has always been – exploitation of the weak and powerless.

February 12, 2022 8:12 pm

The slave trade went to ALL of the New World, and El Niño would not affect all areas uniformly, least of all North American colonies/states, who received the fewest slaves.

Interesting proposition, but irrespective of weather as it may have influenced the ebb and flow of transAtlantic traffic, it misses the greater issue of the atrocity that was slavery.

Slave to Free

https://www.pbs.org/wnet/african-americans-many-rivers-to-cross/history/how-many-slaves-landed-in-the-us

The most comprehensive analysis of shipping records over the course of the slave trade is the Trans-Atlantic Slave Trade Database, edited by professors David Eltis and David Richardson. (While the editors are careful to say that all of their figures are estimates, they may be the best estimates that we have, the proverbial “gold standard” in the field of the study of the slave trade.) Between 1525 and 1866, in the entire history of the slave trade to the New World, according to the Trans-Atlantic Slave Trade Database, 12.5 million Africans were shipped to the New World. 10.7 million survived the dreaded Middle Passage, disembarking in North America, the Caribbean and South America.

And how many of these 10.7 million Africans were shipped directly to North America? Only about 388,000. That’s right: a tiny percentage.

Number of combatants who died in the American Civil War
Deaths (combined armies) – conventional estimate = 620,000. This is considered a conservative estimate.

Newer revised estimates using comparative census data suggest the number of deaths could have been as high as 850,000 combatant deaths. Plus, civilian deaths are estimated to be about 50,000.

https://www.battlefields.org/learn/articles/civil-war-casualties

https://discovere.binghamton.edu/news/civilwar-3826.html

So roughly speaking, for every one slave brought to the U.S., two men died in battle to free them. Yet today, 160 years later, revisionists demanding reparations and pushing CRT and BLM turn a blind eye to the tremendous sacrifices in blood paid to free black Americans.

Furthermore, most Americans at that time, both north and south, never owned or participated in the slave trade. In addition, millions of non-black Americans immigrated after the end of slavery or are descended from those later immigrants, so these have no part in what occurred prior to their arrival.

This is no excuse for the subsequent unjust treatment of black American citizens or for continued acts of racism on the part of a few bigoted individuals. However, “woke” regressive revisionists have no justification for their egregious, hate-filled assault on American values nor for their attempts to fracture and divide Americans by race or ethnicity. God shows no partiality (Romans 2:11; Ephesians 6:9), and neither should we.

In 21st century America, the party of traditional racism, the Democrats, in their quest for power, still keep a stranglehold on urban blacks, and through their repressive policies continue to destroy the black family, church, culture and dignity. This is even true of many black Democrat leaders.

MarkW
Reply to  Pflashgordon
February 13, 2022 7:03 am

There was also a small number of blacks who owned slaves and a large number of blacks who moved to the US after slavery was abolished.

czechlist
Reply to  Pflashgordon
February 13, 2022 9:29 am

Native Americas, North, South and Central, enslaved their enemies and there is evidence of cannibalism. The white Europeans did not introduce slavery to the new world. Africans captured their brothers and sold them to Arabs long before the Americas were discovered.
Democrat politicians need slaves today as urgently as they did over 150 years ago.

Reply to  Pflashgordon
February 13, 2022 11:32 am

As I posted above:

The first shipload of African captives to the British colonies in North America arrived at JamestownVirginia, in August 1619, but for most of the 17th century, European indentured servants were far more numerous in the North American British colonies than were enslaved Africans. However, after 1680, the flow of indentured servants sharply declined, leading to an explosion in the African slave trade.”

From the same source, https://www.history.com/this-day-in-history/congress-abolishes-the-african-slave-trade, states that England is responsible for 3,000,000 of the 4,000,000 slaves imported into the American Colonies.

From your description, I doubt that slave database includes all of the enslaved non-Africans brought to America or captured in North America.
Especially since the bulk of trade in enslaved Africans brought to America occurred after 1680 and importation of slaves was stopped in 1808.

Ed B
February 12, 2022 8:24 pm

Umm. There is this small matter of the Royal Navy’s West Africa Squadron, established in 1808 to crush the slave trade. That would be a pretty important factor, along with the never ending diplomatic efforts to get the U.S. and other European countries to ban the slave trade, so the Royal Navy could seize ships under those flags. As the effectiveness of those measures waxed and waned rapidly with changes of commanders and changes of government (British and foreign) you would have to first control for those effects.

And as to drought causing the Syrian civil war, it couldn’t possibly have anything to do with the fact that the population increased from 2 million in 1935 to 21 million in 2010 because, as we all know, the natural water supply increases with population. No, it must be due to drought caused by climate change.

Reply to  Ed B
February 12, 2022 10:52 pm

Didn’t have to apply very much diplomatic pressure to the US – which, per the Constitution, banned the slave trade in the same year as the establishment of the Squadron.

Crisp
Reply to  Ed B
February 13, 2022 12:15 am

And Obama deciding to support the rebels (who were in fact Islamic extremists) also didn’t help. Bizarre that he was fighting the same people on one side of the Syria-Iraq border as he helping on the other side. That guy was a genius.

griff
Reply to  Ed B
February 13, 2022 12:56 am

Indeed.

There is a moving memorial to a young officer who died while serving as part of that force in the parish church of Wareham, Dorset, England.

February 12, 2022 10:42 pm

What’s with that throw away line in Original Post about the Syrian War being “exasperated by extreme drought”? The “flood” of weapons introduced there has been what has “exasperated” the conflict.

DF12C6B1-945E-46C4-A2D9-FAC6FC7CF2D0.jpeg
MarkW
Reply to  gringojay
February 13, 2022 7:07 am

Protecting property is a bad thing?

Reply to  MarkW
February 13, 2022 10:12 am

Even Canada is in the best of hands,

781DB497-9C03-492B-BD35-3567F4CA9E72.jpeg
February 12, 2022 10:44 pm

Well, climate change did drive the slave trade.
The little ice age caused mass migration out of Europe to North America, central and South America, where those Europeans died in droves from tropical diseases, and so they turned to black Africans.

Isn’t this standard history?
Climate change actually is racist, but it’s when it’s getting colder, as always.

tonyb
Editor
Reply to  Pat from kerbob
February 13, 2022 1:52 am

Until well into the 19th century much of Africa was impenetrable to the Europeans although obviously coastal areas were well visited earlier than that.

As such very many of the slaves they traded in -at least in the early days- may have been the victims of wars between African tribes or provided by Arab slavers with long standing connections .

As such it might be interesting for this study to determine if part of the the slave trade was as a result of wars increasing between indigenous communities due to say Drought caused by changing weather patterns which reduced food availability.

Slavery has unfortunately always been there but perhaps at times it increased due to weather conditions which made the provision of slaves to slave traders of whatever nation easier.

The trade in white slaves from Europe should also be tied into this. Did wind directions change, meaning the Barbary pirates could range further afield?

You would hope that with present day resources we could do more to prevent this trade continuing as some sources say that currently there are up to 45 million slaves

Slavery in the 21st century – Wikipedia

tonyb

Reply to  tonyb
February 13, 2022 9:59 am

Yes, Europeans for the most part didn’t go on slave raids in Africa, they were brought to the ports by other Africans.

But my point was just that all the indentured Europeans struggling to go elsewhere to find a better life during the LIA were much more susceptible to diseases like malaria so they turned to African slaves on the assumption of better resistance.
So from that perspective, Americas current race issues are due to malaria.

Same sort of interesting tidbit of climate history is the rise of Islam. The Arabs were always fewer in number and used as mercenaries. Then the cold period after the RWP weakened the Roman’s and Persians, then plague and constant war flattened them further such that the Arabs swept them all away.

Cold climate always means upheaval

So I hope it stays warm

Crisp
February 13, 2022 12:20 am

There is a clear negative correlation between the decline in the slave trade and global warming, and between the decline in piracy and global warming. For the sake of the planet, we must act fast to reverse both these declines. 97% of scientists agree (probably).

H.R.
Reply to  Crisp
February 13, 2022 6:50 am

Oh, I must disagree, Crisp. Piracy has been increasing at an alarming rate.

But it’s all our own fault. After all, we elected them.

michel
February 13, 2022 1:35 am

It would be interesting to study whether there are any climate correlations with the Islamic trans-Saharan slave trade of Africans. It was on a huge scale and lasted much longer than the trans-Atlantic one. The impact of global climate fluctuations between 700 and 1800 should be clearly visible, if there was any impact.

After 1800 you would have to reckon with the British program of abolition of the slave trade in their African territories – from what I have read this would have had a substantial impact on the trans-Sahara trade after the middle of the 19th century.

Ed Zuiderwijk
February 13, 2022 2:09 am

It appears it was the save traders who discovered America. O, and the slave trade of East Africa to the Arab world predates the Atlantic trade by roughly 900 years. Was it similarly affected by changing weather patterns?

February 13, 2022 2:44 am

Why were they surprised at how detailed the ships logs were? Of course they recorded the weather and details of the cargo. What do the authers think logs are for?
They need to get out more.

They also need to remember that the ships transported people who were already enslaved, the crew didn’t go off into the interior and capture anyone, they bought at the coastal slave market and sold on at the other end of the voyage, or even just hired the ship to a slave merchant organisation.

John Hultquist
Reply to  Oldseadog
February 13, 2022 9:23 am

Logs were – – well, pieces of logs. Thrown off the stern they were used to note speed, that was then recorded in a book — called a logbook or just log.

Reply to  Oldseadog
February 13, 2022 9:26 am

“What do the authers think logs are for?”

Modern scientism doesn’t like the old stuff, especially from anytime before they took control of the data. It’s all too “real world” for the Alarmatologs, it hurts their heads.

I recently read an article from the Morning Chronicle of 1817, (a London newspaper that doesn’t exist anymore), the UK was having a very cold time of it and back then they were also concerned about the ice on the St Lawrence river not breaking up until the first week of May, and the ever increasing mass of the glaciers in the Alps.

“The vessels from England and Ireland, which arrived at Quebec, all concurred in their accounts of the dangers which they encountered and the cold which they suffered.

In fine, it would appear that the ice in those regions had lately accumulated to so alarming a degree, as to threaten a material change in all the adjacent countries, to verify the theory of those observers of nature who have said that the extreme cold of the North is gradually making encroachments upon the extreme heat of the South.”

They finish by calling for “every effort to which human ingenuity and strength are competent, to be exerted for the purpose of counter-acting the growing evil”

Reply to  Climate believer
February 13, 2022 10:05 am

Yes, cold everywhere
Which is why the French were only too happy to trade Lower Canada/ Quebec for a little island in the Caribbean where sugar grew

Tom
February 13, 2022 7:11 am

Perhaps the authors of the study might expand to include the climate and Arabs Muslim slave trade that existed for approximately six centuries prior to European voyages of discovery starting in the 1450s….but that might hinder the ideological narrative and goals of the study.

February 13, 2022 7:51 am

“Learning from the past”
If only…

2hotel9
February 13, 2022 8:04 am

They had my interest right up to this point, “amid a warming future”. Not wasting time on politically driven crap. If it was a real analysis of actual historical events it would be worth a read. When you begin with leftist political dogma there is no credibility. I got 400 odd berdan primed pieces of brass to decap and clean, I’ll spend the time it would take to read their “study” in doing that. And I hate decapping berdan cases.

February 13, 2022 10:46 am

“The study found that El Niño can be used as a proxy — much like tree rings and corals — for historical rainfall and temperature patterns in West Africa.

The authors used reconstructed El Niño indices and the Slave Voyages dataset to examine the relationship between El Niño and the trans-Atlantic slave trade.”

“The trans-Atlantic slave trade began in the 1400s, but instrumental rainfall data only goes back to around the 1800s,” said lead author William Turner IV, a Ph.D. student at UC Davis in the Department of Land, Air and Water Resources. “To fill this data gap, we relied on the proxy association between El Niño and rainfall. We found that during El Niño, West Africa experiences drier conditions.”

Stacked proxies. One set of data is estimated via proxy. That new dataset is then used as a proxy to generate another dataset…
Sounds like a recipe for idiocy.

In January 1807, with a self-sustaining population of over four million enslaved people in the South, some Southern congressmen joined with the North in voting to abolish the African slave trade, an act that became effective January 1, 1808.”

So much for “Trans-Atlantic” slave trade bringing slaves to America. That ended for America in 1808.
England followed shortly thereafter with a similar law banning slave trading.

Actions that eliminate the need for imported slaves and diminish the shipping available to transport slaves.

Somehow, I doubt the authors investigated drought or rainfall conditions for all of the countries still accepting slaves.

The same authors who postulate that droughts diminished the need for slaves, yet the entire slave trade in Africa was/is not based upon farming conditions elsewhere.

More woke ignorant student researchers inventing history, causes and results so they can publish a paper.