Talk:African humid period/Archive 1

Archive 1

When did it end?

The sentence "the African humid period ended about 6,000-5,000 years ago[9][326] around 5,500 years before present" is a bit confusing/double. No need to state two similar dates. Unclear if the second source has a better uncertainty estimate. If you want to state multiple estimates, it should be in a separate sentence. The rest of the sentence is also difficult to follow, partially because of the large amount of mid-sentence sources. Femkemilene (talk) 13:35, 10 January 2019 (UTC)

@Femkemilene: One frequently cited source (Menocal et al. 2000) gives "6,000 - 5,000 years ago" but many other sources say "around 5,500 years ago". I am not sure how to formulate this, I agree the current version is somewhat unclear. Jo-Jo Eumerus (talk, contributions) 21:15, 10 January 2019 (UTC)

A 500 year margin of error is surely not surprising for this far back, especially for an "event" that was presumably pretty gradual. Presumably these are just different ways of saying the same thing: "ended around 5,500 years ago, somewhere between 6,000-5,000 years ago.[9][326]" maybe reads better. Johnbod (talk) 03:39, 11 January 2019 (UTC)

I think that is indeed an improvement. If the 5000-6000 is a formal uncertainty estimates (which I doubt, considering it's a gradual effect), you could say 5500 (5000 - 6000) instead. My preference is only mentioning the 5000-6000. Femkemilene (talk) 08:49, 11 January 2019 (UTC)

Part of the issue (as noted in the chronology section) is that it's not actually clear if the end was gradual or sudden. And there is also the question whether it ended in the same manner and at the same time everywhere. Jo-Jo Eumerus (talk, contributions) 15:41, 11 January 2019 (UTC)

GA Review

This review is transcluded from Talk:African humid period/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Jens Lallensack (talk · contribs) 10:26, 10 March 2019 (UTC)

Will start reading soon, but I may take a while, as it is a long article! --Jens Lallensack (talk) 10:26, 10 March 2019 (UTC)

@Jens Lallensack: Thanks. Yes, this is the longest article I've ever written. Jo-Jo Eumerus (talk, contributions) 10:58, 10 March 2019 (UTC)

I'm sorry that I didn't get far yet. Here is the first bunch of points:

• It involved changes in Earth's orbit around the Sun, changes in vegetation and dust in the Sahara that altered the African monsoon, the disappearance of much of the Sahara desert which was replaced by grassy vegetation, trees and lakes and the settlement of the former desert by various animals and humans, who survived as hunter-gatherers. – You do not differentiate between causes and effects, why? I would have expected that both are treated separately.

  There is kind of a sorting with the cause being first and the effects second. First part is the ultimate cause, second part the feedback effects, third the actual changes and fourth their ramifications. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

  Yes, but that sould be reflected in the wording, not only the order. I can only give suggestions, depends on you what you make of it. --Jens Lallensack (talk) 16:44, 24 March 2019 (UTC)

  Well, I do think that the "interesting" bits needs to stay in, as otherwise a reader unfamiliar with the topic has no idea that there is more to this than a technical article on a climate anomaly thousands of years ago. That necessarily restricts how much of it can be rewritten. Part of the point of a lead section is to hook a reader in to the article. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

  I did not mean to remove something, I merely see a prose issue. What about "It was caused by changes in Earth's orbit around the Sun, and involved changes in vegetation …"? --Jens Lallensack (talk) 02:58, 25 April 2019 (UTC)

  Maybe I got it - check my edit to the lead section. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• who survived as hunter-gatherers. – why not simply "were hunter-gatherers"? Was the environment especially hostile that we need the word "survive"?

  Yeah, that wasn't intended. Changed. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• It has had profound effects on present-day Africa – as only culture stuff is listed, maybe specify with "present-day African culture"? As Ancient Egypt and the Golden Age myths impacted not only Africa, maybe you can even skip the "present-day Africa"?

  My concern with "present-day African culture" is that it's a bit too specific IMO, in terms of timespan. I think that Ancient Egypt should still be considered "Africa". As for the Golden Age myths ... I dunno how to formulate this. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• and had extensive dune fields, many lakes and rivers such – think you need a ";" here instead of the ",". With the latter, it reads like a listing, which misleads the reader.

  Remedied this. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• The African humid period commenced about 14,600–14,500 years ago at the end of Heinrich event 1 and concomitant to the Bølling-Allerød warming, rivers and lakes such as Lake Chad formed or expanded – not especially good with English grammar, but shouldn't this sentence start with "As the African humid period …", or alternatively "with rivers and lakes"?

  Does it work better with a ";" here than a ","? Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• but the end of the African humid period came about 6,000–5,000 years ago during the Piora Oscillation cold period when the Sahara occupied its present position. – I would start a new sentence here.

  So done. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• such as these in the Cave of Swimmers – "such as those"?

  Done. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• which shifted the season during which Earth is closest to the Sun towards Northern Hemisphere summer during the early Holocene – a bit concoluted, lot of stuff put togehter here, not so easy to read. Why not moving the "during the early Holocene" to the sentence "The African humid period commenced …"? Would be more helpful there.

  Er, the Bølling-Allerød occurred during the late Pleistocene; the AHP was already set in when the Holocene started. Would it help to cut "Northern Hemisphere"? Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• This was not enough to make the Sahara disappear – Suggest "This alone was not enough" for clarity. Otherwise one would assume that it means that the Sahara did not disappear completely.

  Added. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• Suggest to link or explain petroglyphs

  Linked. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• The terms "Léopoldvillien"[19] and Ogolien [fr] has been applied – have been

  Fixed. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• The terms "Léopoldvillien"[19] and Ogolien [fr] has been applied to the dry period in the last glacial maximum. – These terms are not mentioned again, so I wonder why they are relevant here? Reducing complexity would make it easier for readers.

  That section discusses the terminology, so indicating that it's called that way seems pertinent even if they aren't discussed again. Not entirely sure though. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• You use a mixture between American and British English.

  Sorry, but I don't know much about which is which in many circumstances. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• lake development in Tibesti and Jebel Marra mountains – do we need to have a "the" inserted here?

  Yes, added. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• In addition to drought, glaciers were active in the Bale and Semien Mountains of Ethiopia during the last glacial maximum – I'm confused about the "in addition". To what do drought + glaciers add up? Hostility? What does it want to tell us?

  Changed to "finally". Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

--Jens Lallensack (talk) 17:43, 16 March 2019 (UTC)

@Jens Lallensack:Well, it is a long article, as you said. This doesn't need to be done urgently. Jo-Jo Eumerus (talk, contributions) 20:56, 16 March 2019 (UTC)

• Due to the phenomenon called precession – this is wordy but does not explain anything; I also would not call it a "phenomenon", as it is more of a condition?

  I've shortened this; I am not sure if we want to explain what precession is in this article. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• This effect was strengthened by the increased summer insolation thus leading to a stronger monsoon that also reached farther north. – This, and the whole paragraph, is basically a repetition of what was already said. Suggest to merge it with the preceding paragraph.

  See, I was thinking the preceding paragraph was a description of how Earth's orbit changed, while this one is about the effects thereof. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• Obliquity and precession are among the foremost Milankovich cycles – these are not cycles, these are effects resulting in the cycles.

  Fixed. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• the ITCZ – I would really spell this out, makes it more accessible.

  Done, should it also be changed on every mention? Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• correlate to changes – correlate "with"?

  Changed. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• Contrarily, northward transport of moisture during autumn and spring directed by throughs close to Northern Africa has also been proposed to explain the increased precipitation and its underestimation by climate models. – I don't get this

  Rewrote this a bit, does it work better now? Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• increased water supply from montane region may have assisted – "regions"?

  Fixed. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• the atmospheric boundary layer. and – why the dot?

  Typo, removed. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• according to Kuhlmann et al. and Hoffman et al. – Maybe delete, as you do not name authorities in other sections?

  Sure, done. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• brown or yellow vegetation communities – what is this, can you link/explain?

  Oddly, neither the first source nor the source that source refers to explain this. I am guessing that it refers to the colour of the plants, though - not sure how to clarify. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• Pollen data often showing a dominance of grasses over humid tropics trees. – "show"?

  Fixed. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• Nevertheless, the Sahara did not become entirely homogeneous – too imprecise, maybe "climate of the Sahara"?

  Specified. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• its pollen in sediment core – "cores"

  Done. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• Earlier humid periods in the Sahara may have allowed species to cross the now-desert. – This means that the Holocene humid period did not?

  Not as far as we know; the thinking might be that all species exchanges happened in the earlier humid periods and that the Holocene AHP didn't add anything. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• A reduction in open grasslands caused by the African humid period may explain a population bottleneck in cheetahs at the start of the humid period – So they did not move northwards? I thought there was a lot of grass land during the period?

  This is going to be tough. This source believes that there may have been less grassland during the AHP. Other sources say it expanded. Seems like at first it may have shrunk; the source does not specify but I made a small change. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• both in Egypt and both feature archeological sites – "featuring"?

  Done, not sure if "feature" works as well however. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• the rivers were often connected between each other – "with each other"?

  "With" sounds a bit too strong for this context, as they weren't tributaries apparently. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• the rivers were often connected between each other through alluvial fans – Could you check if this should say "alluvial plains"?

  Checked, it says "alluvial fans". Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• Some rivers discharging through Bay of Arguin – add "the"

  Done. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• and later pastoralists, – suggest "and, later, pastorialists"

  Done. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• as well as in Uan Tabu and Takarkori rock shelter both also in the Acacus Mountains – needs a comma?

  Done. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

• hence it is also known as "aqualithic" – what is "it" referring to, the whole humid period? --Jens Lallensack (talk) 16:44, 24 March 2019 (UTC)

  Specified. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

@Jens Lallensack:Thanks. Due to time constraints, I'll reply tomorrow. Jo-Jo Eumerus (talk, contributions) 21:14, 24 March 2019 (UTC)

@Jens Lallensack: OK, now actioned these issues. Jo-Jo Eumerus (talk, contributions) 07:17, 25 March 2019 (UTC)

@Jens Lallensack: CC'ing you about this conversation on the "implications for future climate change" section as William M. Connolley flagged a couple of problems there. I think I solved one of them but I am not so sure on the other. Jo-Jo Eumerus (talk, contributions) 16:27, 12 April 2019 (UTC)

I have currently no opinion here, I did not reach that section yet. --Jens Lallensack (talk) 02:58, 25 April 2019 (UTC)

• Waters from the Nile filled depressions like the Fayum Depression – dot missing

Done. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• relative to that of the White Nile – dot missing

Done. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• This overflowing large was filled with freshwater – what is a "large"?

Added. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• The African humid period ended about 6,000-5,000 years ago around 5,500 years before present and after a vegetation decline sand claimed the Sahara which became barren, accompanied by increases in dust export from the now-desert and from dried up lakes. – Long, complicated sentence that is hard to read.

I've cut that sentence up a bit. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• in a more protracted fashion, Distinct – full stop here?

Yes, done. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• two different insolation thresholds. – very technical language. Should be explained in language comprehensible to non-scientists.

Rewrote this a bit but it's not going to be easy to find an alternative to "insolation"/"irradiation". Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• Increased autocorrelation – Again; translate into comprehensible language?

That's a tough one. Even I had to look up "autocorrelation" and it's apparently not something that's easily "translated" as each definition I've seen is just as technically worded; I've stripped it out for the time being. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• calibrated years ago – can this be explained at first mention?

Added a link at first mention. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• radiocarbon years ago – ditto

Added a link here as well. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• The now dried out basin was now exposed – two "now" mean different times here? Confusing.

Removed one "now". Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• which blew dust out of the dried basin and is the single largest source of dust in the world. this change in tense seems to make no sense.

Changed this. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• A 4.2 kiloyear event is recorded in dust records and the Mediterranean and might – I don't understand.

Rewritten this a little; is it clearer now. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

• If you wish to submit this to FAC in the future, I would seriously shorten it beforehand. It became too long for a single article. That is ok for becoming GA. --Jens Lallensack (talk) 02:58, 25 April 2019 (UTC)

  @Jens Lallensack: Thanks. Replied and addressed the comments. Regarding a potential FAC, according to Wikipedia:Featured articles/By length it would actually only be the thirty-longest FA if it were to pass at the current length ... but I see the point that such a super long thing is hard to review especially as it might become even longer in the future as more science about this is written. Jo-Jo Eumerus (talk, contributions) 06:22, 25 April 2019 (UTC)

It always depends on the article, whether excessive length is warranted for the topic or not. The last article I witnessed to fail at FAC just because of length was National Front (UK), which is much shorther than this one. --Jens Lallensack (talk) 21:21, 21 May 2019 (UTC)

• @Jens Lallensack:Eh, I'll see about this next Christmas, when the next big update (with papers published in 2019) is due. Jo-Jo Eumerus (talk, contributions) 21:50, 21 May 2019 (UTC)

• The end of the humid period appears to reflect the changes in insolation during the Holocene[78] with a progressive decrease thereof leading to decreased insolation gradients between Earth's hemispheres[470] but appears to have been much more abrupt than the insolation changes. – Sentence is very long and difficult to read. I don't understand the last part "but appears to have been much more abrupt than the insolation changes" – this reads to me like "the decrease of insulation was more abrupt than the insolation changes", which makes no sense.

  I've split it up a bit. Jo-Jo Eumerus (talk, contributions) 21:50, 21 May 2019 (UTC)

• the ITCZ – suggest to spell it out.

  Spelled it out everywhere. Jo-Jo Eumerus (talk, contributions) 21:50, 21 May 2019 (UTC)

• There might be differences between plants at higher versus these at lower latitudes, – perhaps just "differences between plants at higher and lower latitudes"?

  Yes, done. Jo-Jo Eumerus (talk, contributions) 21:50, 21 May 2019 (UTC)

• Decreases in polar insolation through altered cosmic ray fluxes … – remainder of the sentence does not seem complete, as it becomes a list without connections.

  That's because it is part of the list. Jo-Jo Eumerus (talk, contributions) 21:50, 21 May 2019 (UTC)

  I mean "thus stronger" does not connect well to the preceding part of the sentence. Needs slight reformulation I would say. --Jens Lallensack (talk) 17:55, 23 May 2019 (UTC)

  Did a small rewrite there. Jo-Jo Eumerus (talk, contributions) 19:03, 23 May 2019 (UTC)

• Additional feedback processes may have included the drying of soils and loss of vegetation after decreased rainfall[100] would led to wind-driven deflation of the soils. – "which would led"? --Jens Lallensack (talk) 21:21, 21 May 2019 (UTC)

  Remedied. Jo-Jo Eumerus (talk, contributions) 21:50, 21 May 2019 (UTC)

• including large-scale deforestation and for iron production during the Iron Age. – "and" is a word too much?

  Yes; removed it. Jo-Jo Eumerus (talk, contributions) 19:03, 23 May 2019 (UTC)

• Similar changes have been observed on the Adamawa Plateau[484] (Cameroon[466]) – Did you cite [466] just to source the fact that the Plateau is in Cameroon? This is not necessary.

  Aye, because the page of the source that discusses "Adamawa Plateau" does not mention that it is in Cameroon. Jo-Jo Eumerus (talk, contributions) 19:03, 23 May 2019 (UTC)

• between human expansion in Cameroon and environmental degradation – "Degradation" is always something negative. "Change" would be neutral (a desert is also an environment!). If humans had no influence, than we should use "change" imho. "Degradation" thus implies that humans had an influence, which is precisely what the sentence questiones (no correlation). Thus use "change"?

  I dunno, the sources that discuss the AHP often use "degradation" to refer to the desertification/drying. Jo-Jo Eumerus (talk, contributions) 19:03, 23 May 2019 (UTC)

• Climate-mediated feedbacks may have increased the fallout in East Africa – Too much technical speach I would argue. What kind of fallout?

  Replaced with "impact" and expanded a bit. Jo-Jo Eumerus (talk, contributions) 19:03, 23 May 2019 (UTC)

• In the Sudanian and Sahelian savannah on the other hand human activity seems to have had little impact – "on the other hand" indicates that human activity had an impact elsewhere. But no evidence for this was provided in the preceding sentences (just one study that did not find a correlation, and some facts without explicit interpretation in this direction).

  This is somewhat complex. Basically, there is an open controversy about how much human activity impacted on the environment in Central Africa and that controversy is not settled. Elsewhere on the other hand evidence for human impact is much more scant. The source cited for this statement is summarizing other research articles. Jo-Jo Eumerus (talk, contributions) 19:03, 23 May 2019 (UTC)

• Claussen et al. – I was told we should avoid "et al." in Wikipedia, as it is too technical. --Jens Lallensack (talk) 18:12, 23 May 2019 (UTC)

  I suggest "and colleagues" instead of et al. --Jens Lallensack (talk) 19:43, 23 May 2019 (UTC)

  @Kens Lallensack: Done. Jo-Jo Eumerus (talk, contributions) 19:47, 23 May 2019 (UTC)

  @Jens Lallensack: Jo-Jo Eumerus (talk, contributions) 19:48, 23 May 2019 (UTC)

  Hrm, would it work better to spell the names out? Jo-Jo Eumerus (talk, contributions) 19:03, 23 May 2019 (UTC)

• @Jens Lallensack: Jo-Jo Eumerus (talk, contributions) 19:03, 23 May 2019 (UTC)

• Such human migrations towards more hospitable conditions along rivers and the development of irrigation also took place along the Euphrates River, Tigris River and Indus River, leading to the development of the Sumerian and Harappan civilizations. – Sumer started 6500 years ago, before the end of the humid period and much earlier than the Harappan civilization? Furthermore, I think the info that the Harappan civilization used irrigation is outdated, see here for a summary: [1]

  I dunno. Sumer suggests that the society there started a few millennia later, or at least the urban aspects. Also, the Arabian AHP might not have ended at the same time as the Africa one. I am guessing this is just the problem with linking two separate events with an uncertain chronology but I don't recall seeing any sources that explicitly rule out a connection between climate drying and the onset of Mesopotamian civilization. Regarding the Harappan civilization, is that study the last word on the irrigation question? The source in the article is from one year later and says The increasingly arid conditions at the end of the African Humid Period forced human agropastoral societies to improve their organization in order to optimize natural resources, in particular freshwater supplies (7). As a result of growing demographic pressure in an environment that was again becoming hostile, Neolithic communities were forced to concentrate in river valleys and to develop irrigation systems. These complex transformations help explain the rise of the Egyptian, Sumerian, and Harappan civilizations that flourished along major rivers such as the Nile, Euphrates, Tigris, and Indus. Jo-Jo Eumerus (talk, contributions) 09:57, 30 May 2019 (UTC)

  I think so, the paper cites other works supporting the lack of irrigation. But should be checked in any case. --Jens Lallensack (talk) 12:46, 30 May 2019 (UTC)

  @Jens Lallensack: Hmmm. Well, the article here probably should still say that the end of the AHP is linked to the onset of the Harappan civilization. I am not sure how to separate the "irrigation" aspect; maybe say "often with irrigation" rather than just "irrigation"? Jo-Jo Eumerus (talk, contributions) 13:52, 30 May 2019 (UTC)

  Yes, formulating it a bit less definitive should do the trick! --Jens Lallensack (talk) 13:56, 30 May 2019 (UTC)

• the development of elites the increased presence of human – misses a ","?

  Yes, added it. Jo-Jo Eumerus (talk, contributions) 09:57, 30 May 2019 (UTC)

• desert i.e. a – also misses two ","?

  Also added. Jo-Jo Eumerus (talk, contributions) 09:57, 30 May 2019 (UTC)

• occurs through different methods – I guess you mean "mechanisms"?

  Yes, changed that. Jo-Jo Eumerus (talk, contributions) 09:57, 30 May 2019 (UTC)

• That's all, finally. I'm relieved to got this done! --Jens Lallensack (talk) 09:24, 30 May 2019 (UTC)

  Thanks for the review Jens Lallensack. Jo-Jo Eumerus (talk, contributions) 09:57, 30 May 2019 (UTC)

• The article is promoted now. Congratulations! For further improvement, I would strongly suggest to find ways to shorten this article, moving text into sub-articles and such. --Jens Lallensack (talk) 14:02, 30 May 2019 (UTC)

Merger discussion with Neolithic subpluvial

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

---

As Johnbod noted in Template:Did you know nominations/African humid period, Neolithic Subpluvial appears to cover the same ground as this article (Some sources), except that that article is much shorter and its title less commonly used in academic literature: few hits for Neolithic Subpluvial, far more African humid period hits. Thus, I would recommend that Neolithic Subpluvial be redirected/merged into African humid period. Jo-Jo Eumerus (talk, contributions) 16:41, 6 January 2019 (UTC)

• Support per nom. Johnbod (talk) 16:44, 6 January 2019 (UTC)
• Strong Oppose. African humid period is 200 thousand bytes already and hard to read with 48 sections. This article should itself be split into smaller articles instead of merging other articles into it.AhmadLX (talk) 01:27, 21 January 2019 (UTC)

  Actually, much of that length it dies to citation templates and references; the actual text is only 71,600 - 85,000 characters long depending on how you count it ... although WP:SIZERULE does certainly recommend that splitting should be considered for an article 60,000 - 100,000 characters in length. Letting a duplicate topic stand (and from what I can tell, most of the content is already duplicated anyhow) is probably not the right way to go about it, though. Jo-Jo Eumerus (talk, contributions) 06:36, 21 January 2019 (UTC)

Hi. Yes, in that case, best option would be to delete the duplicate article i.e Neolithic subpluvial without importing minor details or sources that are unique to it. Then this article should better be split as well. Just have a look at it, its lead is equivalent to modest sized article in itself, and then 48 sections. Few people would want to read it whole. Thanks. AhmadLX (talk) 22:29, 21 January 2019 (UTC)

No it would not! Most Wikipedians fail to realize this, but few readers want to or do read any longish article right through, and our house style is to provide a summary in the lead and then a TOK and sections so that readers can easily access what information most interests them. "Too long to read whole" is not an argument for reduction or splitting if this is not easy to do, or for excluding information in a fork article. How would you suggest the article is split? On a quick look, I didn't see an obvious way. The other article is pretty short, & I suspect adding the unique material from it would not increase overall size much. As the auther of the new article, Jo-Jo Eumerus is much the best person to do this. Johnbod (talk) 00:59, 22 January 2019 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Potential sources to use

"Will Greenhouse Green the Sahara?". Jo-Jo Eumerus (talk, contributions) 05:57, 30 April 2019 (UTC)

And this if we want more material on the research history. Jo-Jo Eumerus (talk, contributions) 20:25, 4 May 2019 (UTC)

Another source is this if we want to correlate events in disparate parts of the Sahara, and this one for the origin of sickle cell disease. Jo-Jo Eumerus (talk, contributions) 19:21, 11 August 2019 (UTC)

Finally, this one. Jo-Jo Eumerus (talk, contributions) 10:54, 12 August 2019 (UTC)

Two more for possible use. Jo-Jo Eumerus (talk, contributions) 20:48, 13 October 2019 (UTC)

Yet another one. Jo-Jo Eumerus (talk) 18:07, 13 November 2019 (UTC)

Nomination of Neolithic Subpluvial for deletion

A discussion is taking place as to whether the article Neolithic Subpluvial is suitable for inclusion in Wikipedia according to Wikipedia's policies and guidelines or whether it should be deleted.

The article will be discussed at Wikipedia:Articles for deletion/Neolithic Subpluvial until a consensus is reached, and anyone, including you, is welcome to contribute to the discussion. The nomination will explain the policies and guidelines which are of concern. The discussion focuses on high-quality evidence and our policies and guidelines.

Users may edit the article during the discussion, including to improve the article to address concerns raised in the discussion. However, do not remove the article-for-deletion notice from the top of the article until the discussion has finished.

Adding a notice here as well as this page is pertinent to the discussion. Jo-Jo Eumerus (talk, contributions) 11:53, 15 June 2019 (UTC)

Discussion at Talk:Neolithic Subpluvial#RfC: Defining the relationship between African humid period and Neolithic Subpluvial (including merging, redirecting or redefinition if they are warranted)

 You are invited to join the discussion at Talk:Neolithic Subpluvial#RfC: Defining the relationship between African humid period and Neolithic Subpluvial (including merging, redirecting or redefinition if they are warranted). Jo-Jo Eumerus (talk, contributions) 15:13, 8 July 2019 (UTC)

Open access links

OAbot finds 15 open access links for sources cited in this article, I recommend adding them: https://tools.wmflabs.org/oabot/process?name=African+humid+period Nemo 05:48, 27 July 2019 (UTC)

I'll admit that I am not sure of the copyright status of many of these links. Jo-Jo Eumerus (talk, contributions) 10:27, 27 July 2019 (UTC)

Did a bit more reading:

1. 1 is already open access.
2. 2 takes too long to load.
3. 3 - #5, #9-#11, #13 and #15 look like it's a copy of a final text, not of any kind of draft, and according to the Sherpa pages for Elsevier the publisher does not necessarily allow it.
4. 6 is broken.
5. 7, #8 and #12 I am not sure if it's a final text or draft. Also Elsevier where the distinction is important.
6. 14 I am not sure about the policies of the publisher.

Jo-Jo Eumerus (talk, contributions) 10:36, 27 July 2019 (UTC)

Thanks for checking. On slowness, webpagetest.org doesn't report any problem, maybe it was transient or limited to your network? For those you are unsure about, if the universities are doing it it's because they can: for instance https://hal.archives-ouvertes.fr/ is allowed by various national licenses for green OA as well as well as the famous article 30 of the Loi pour une République numérique (similar laws exist in various countries). Nemo 08:22, 29 July 2019 (UTC)

Thanks. I'll be busy on other WP projects, though, so someone else will have to add any links. Jo-Jo Eumerus (talk, contributions) 09:47, 29 July 2019 (UTC)

Sure. There's no hurry. Nemo 07:52, 30 July 2019 (UTC)

Extinct animals

This source implies that Pelorovis and Sivatherium were among the Saharan species. In addition, Equus hemionus, Equus africanus, the extinct aurochs and scimitar horned oryx are stated to have occurred in Arabia. Parking this here as I am a little unclear on the sources-for-this-source; if there is material endorsing these claims it should probably be added. Jo-Jo Eumerus (talk, contributions) 09:51, 12 August 2019 (UTC)

First sentence

I changed the first sentence from

The African humid period (AHP) is a climate period in Africa during the Holocene during which northern Africa was wetter than today.

to

The African humid period (AHP), roughly lasting from 14,600 years ago to 5500 years ago, was the most recent climate period in which northern Africa was wetter than today.

because:

• The span of a period is its most basic attribute and as such should be given in the first sentences describing a period.
• The first sentence dating AHP as 'during the current geological epoch during which northern Africa was wetter than today' isn't very helpful.
• Otherwise a reader has to read 132 words of the leading segment to learn when AHP started started.
• Otherwise a reader has to read 202 words of the leading segment to learn when AHP ended.
• Otherwise the first sentence is objectively incorrect as the Holocene only started ~11,650 cal years BP.
• The article should make clear that AHP is not the only humid period, but only the most recent one.

Please address these issues before before changing my edit.Kuiet (talk) 00:59, 16 February 2020 (UTC)

@Kuiet: I see two issues with this rewrite. One, as you can see from the "End - Chronology" section the timing of the end of the AHP is somewhat contested; 5,500 years ago is certainly the most common estimate but hardly the only one. "was the most recent climate period in which northern Africa was wetter than today" is somewhat misleading; there were wetter periods than "today" in Africa that are more recent than the AHP, such as the early 20th century pluvial, but which aren't a "green Sahara" period. Jo-Jo Eumerus (talk) 11:12, 16 February 2020 (UTC)

I concur with JJE that the previous sentence was better in terms of prose, and accuracy. In order to write accessibly, we should avoid too many details. Femke Nijsse (talk) 11:21, 16 February 2020 (UTC)

@Jo-Jo Eumerus: I sincerely appreciate your mannered approach. And, indeed, I recognize both your points as valid. I tried to signify the dates were contested by adding the word 'roughly', but if you deem an alternative approach more clear, by all means, implement it. Similarly I agree that 'most recent one' is misleading and should be removed. But I remain strongly in favour of mentioning the start and end dates - whichever ones - before 200 other words.Kuiet (talk) 15:46, 16 February 2020 (UTC)

Well, I don't think that we can accurately summarize the uncertainty of timing within the first sentence w/o making it unduly complex. Also, only a very small part of the Pleistocene included the AHP, so I am not certain on whether it's better to mention it. JoJo Eumerus mobile (main talk) 07:36, 17 February 2020 (UTC)

I am inclined to restore the previous text, but I wonder if there is a better formulation. JoJo Eumerus mobile (main talk) 11:48, 19 February 2020 (UTC)

Sorry for being late in replying. Why do you think mentioning the Pleistocene might be a good idea? Don't restore the previous text since at least the Holocene part is factually incorrect.Kuiet (talk) 22:15, 21 February 2020 (UTC)

Huh? If the lack of "Pleistocene" makes the previous text wrong that sounds like a good reason to add it, no? Jo-Jo Eumerus (talk) 09:11, 22 February 2020 (UTC)

My apologies, it seems I wasn't sufficiently coherent. What I meant to say was:

• Don't put 'Holocene' back, since it's wrong.
• You were the first to mention 'Pleistocene' so in reference to your "Also, only a very small part of the Pleistocene included the AHP, so I am not certain on whether it's better to mention it." I wanted to ask you why/where are you considering mentioning 'Pleistocene'. Not implying mentioning it would be good or bad, I was just plain asking for more info.

But honestly there isn't even really a need for you to explain - I don't want this to turn into an endless conversation and I trust you enough to just go with whatever you decide is best.Kuiet (talk) 16:59, 22 February 2020 (UTC)

@Kuiet and Femkemilene: I've done this edit in an attempt to compromise between some of the issues mentioned here. Jo-Jo Eumerus (talk) 17:28, 15 March 2020 (UTC)

@Jo-Jo Eumerus: Nicely done, thank you.Kuiet (talk) 10:53, 18 March 2020 (UTC)

"Neolithic subpluvial" in the lead

Sorry, but I have to dispute Geoffrey.landis's attempts to include "Neolithic Subpluvial" in the lead for the following reasons:

• There are currently a number of synonyms of AHP listed and there is nothing that would justify singling out this one.
• On the contrary, according to Google Scholar most other synonyms are better known than Neolithic Subpluvial.
• That Neolithic Subpluvial is a redirect to this page is irrelevant. Lead sections are written on the basis of article content, not on whether one term has a page here that is a redirect.
• The exact terminology is a relatively low-importance aspect of the entire topic, thus not lead-worthy.

Thus I don't think the other terms should be mentioned at all. Jo-Jo Eumerus (talk) 11:56, 12 July 2021 (UTC)

If those other terms redirect to this page, then they should be boldfaced in the lede, too. This article is not only the "African humid period" article, it is also the "Neolithic subpluvial" article.

When a user loads an article, the term that they went should actually exist on the page. "You didn't really want the article you thought you loaded, so we decided to load a different article instead; it's up to you to figure out why we picked this article instead of the one you wanted" is not good practice. Geoffrey.landis (talk) 14:56, 13 July 2021 (UTC)

That does not really address the UNDUE issue. Also, WP:R#ASTONISH only endorses a bold mention when it would be a surprising target, but an article with "subpluvial" in it redirecting to one with "humid" isn't, really. Jo-Jo Eumerus (talk) 15:07, 13 July 2021 (UTC)

UNDUE was not addressed because WP:UNDUE was not previously brought up. Using an alternate term a single time in the lede is not an undue violation of neutral point of view.

The text you linked states: "Normally, we try to make sure that all "inbound redirects" other than misspellings or other obvious close variants of the article title are mentioned in the first couple of paragraphs of the article or section to which the redirect goes. It will often be appropriate to bold the redirected term." "Neolithic Subpluvial" is not a misspelling of "African humid period", nor is it an "obvious close variant". Geoffrey.landis (talk) 01:27, 14 July 2021 (UTC)

It was brought up there is nothing that would justify singling out this one. and yes mentioning a rarely used alternative title that is mostly outdated in bold in the first sentence is in fact undue. Jo-Jo Eumerus (talk) 09:02, 14 July 2021 (UTC)

Honestly, a better alternative would be to retarget Neolithic Subpluvial to African humid period#Terminology where it is mentioned. Jo-Jo Eumerus (talk) 09:07, 14 July 2021 (UTC)

We're usually quite liberal with alternative names in the lead and I don't think it would hurt to include some here. Green Sahara also redirects here, for example, and to me at least that's a more familiar term than Neolithic subpluvial or African humid period; it would be helpful to readers to immediately point out that these are all the same concept. – Joe (talk) 15:18, 13 July 2021 (UTC)

Well, I have to strongly oppose Green Sahara because that concept applies to pre-Holocene GS as well but this article only covers the Holocene version. The only reason why it is a redirect is because nobody has bothered to author an article yet and this is the closest related topic. Jo-Jo Eumerus (talk) 15:28, 13 July 2021 (UTC)

Please stop. If you want to continue reverting, please establish a consensus first (which you have not), rather than designating yourself as a self-appointed expert. Until then, please follow Wikipedia standards, which are that inbound redirects are to be mentioned in the first couple of paragraphs of the article. See: WP:R. Geoffrey.landis (talk) 21:41, 23 August 2021 (UTC)

@Geoffrey.landis:Sorry. However, WP:R does not say that it's always appropriate to mention it in the lead - in fact, the guideline says that things like "density of water" are more appropriately not mentioned in the lead and I think it's a better analogue than the parts you mention. And the UNDUE point still stands. Jo-Jo Eumerus (talk) 10:24, 24 August 2021 (UTC)

This is an inbound redirect. The instructions on inbound redirects apply.

The "Density of Water" redirect to "Properties of water" needs no boldface because it is obvious that density of water is one of the properties of water. Are you asserting that it is so obvious that the phrase "Neolithic subpluvial" refers to the African humid period that it is unnecessary to mention it?

I assume you have not read the WP:Undue article, which is about giving appropriate weight to opposing opinions. In any case, six words is not undue weight. Geoffrey.landis (talk) 21:49, 25 August 2021 (UTC)

I did read the part where it says Giving due weight and avoiding giving undue weight means articles should not give minority views or aspects as much of or as detailed a description as more widely held views or widely supported aspects ... Undue weight can be given in several ways, including but not limited to depth of detail, quantity of text, prominence of placement, juxtaposition of statements and use of imagery. (emphasis mine) and that's a problem here since "neolithic subpluvial" is not the most common alternative name by far (Holocene Wet Phase - which is commonly applied to the African/Arabian version, is almost 10 times as common and "Green Sahara" is even more so). That's why I think it shouldn't be mentioned first; either you don't mention it at all and just say "Also known under other names" with a link to the section or you mention Green Sahara first, which has far more claim to the title and is certainly no more clearly connected to "African humid period". Jo-Jo Eumerus (talk) 09:29, 26 August 2021 (UTC)

@Geoffrey.landis: As the person wanting to add something to the stable version that Jo-Jo Eumerus worked on for months, the onus is on you to get a consensus for it, not on them to satisfy your understanding of policy.

Now that I see how many alternative names there are, I think the link in "also known by other names" is a good solution. But to find out that it is also known as the "Neolithic subpluvial" (or "Holocene Wet Phase" etc.), readers currently have to click that link and then click on an easily-missed footnote. The Terminology section is not very long: can we not just put footnotes a and b in the main text? And bold the synonyms that redirect here per MOS:BOLD? – Joe (talk) 11:41, 26 August 2021 (UTC)

To be honest, I've never been happy with shoving the alternative names into a footnote. It can be defootnoted, I think. Jo-Jo Eumerus (talk) 15:25, 26 August 2021 (UTC)

"As the person wanting to add something to the stable version that Jo-Jo Eumerus worked on for months, the onus is on you to get a consensus for it"

No.

Putting a reference to a redirect term in the lede of an article is Wikipedia standard editing practice. Period. Jo-Jo unilaterally deciding that he doesn't like Wikipedia editing policy and NOT doing this requires consensus. Geoffrey.landis (talk) 18:30, 22 September 2021 (UTC)

It isn't a policy. Both WP:R and WP:MOS are guidelines and the former says that "normally" not "always". One can still discuss which term should be given special emphasis if there is more than one candidate term or if WP:UNDUE concerns exist [which is a policy]. Jo-Jo Eumerus (talk) 08:50, 23 September 2021 (UTC)

The distinction between "guidelines" and "policy" is nit-picking, but if you prefer: Putting the phrase in the lede is following Wikpedia guidelines.

"Undue" refers to emphasizing excessive emphasis of minority opinions. One word is not, in any sense of the word, excessive.

I have a suggestion, let's follow Wikipedia policy.Geoffrey.landis (talk) 18:08, 26 September 2021 (UTC)

As said before "neolithic subpluvial" is far from the most commonly used term and putting it in the first sentence is indeed undue. As that policy itself says, "prominence of placement" can be a way to give something undue importance.

This is beginning to go in circles. The current parenthetical which refers people to the other names is fine I think. Jo-Jo Eumerus (talk) 07:42, 27 September 2021 (UTC)

Green Sahara

I added this as an ALTNAME (which is also a redirect and probably is also a contender for COMMONNAME!) before noticing the above thread - so no doubt I'll be reverted! However, just to say that we shouldn't have a link back to the terminology section in the first sentence - per MOS:CIRCULAR. DeCausa (talk) 10:10, 7 October 2021 (UTC)

@DeCausa: See, I was thinking that MOS:SL would apply here rather than MOS:CIRCULAR as it's a section link and not a circular redirect. Green Sahara is certainly a common term but one catch is that it's also often applied to pre-Holocene AHPs which are more tangentially covered here.

I've been dallying with turning Green Sahara into a proper article with a different focus (more anthropology and more Sahara, for instance), actually. Jo-Jo Eumerus (talk) 10:15, 7 October 2021 (UTC)

I've never noticed the last sentence of MOS:SL before. That does seem to override CIRCULAR - which does seem slightly odd but there it is in black and white! This is obviously an area of your expertise (which it isn't for me) - is Green Sahara a different concept to this article? The sources I looked at seemed to use it as a synonym. DeCausa (talk) 10:21, 7 October 2021 (UTC)

@DeCausa:There is a roughly 50-80% overlap, I'd say. That said, AHP also covers East Africa etc. which isn't within the Sahara, and AHP is mainly used for the Holocene GS while GS can also be applied to the Eemian etc. GS. Jo-Jo Eumerus (talk) 15:16, 7 October 2021 (UTC)

Ok, I’ve self reverted the edits I made earlier which included adding “Green Sahara” to the Terminology section (where it’s currently not mentioned). There may be scope for a separate Green Sahara article. However, what I would say is that there needs to be a clearer explanation of “Green Sahara” and its relationship to the article title both in the lead and the body of this article. I certainly found this article looking for information about Green Sahara and would say it’s a more widely known name than the article title. In the article itself it often seems to be used as a synonym for the article title which possibly needs clarifying. For these reasons I think quite a prominent explanation is warranted. By the way - great article! I see it’s pretty much all your work.DeCausa (talk) 16:34, 7 October 2021 (UTC)

File:Africa Climate 7000bp.png

I see that Tobby72 just added File:Africa Climate 7000bp.png to the page. I am not sure if it was already added in the past, but I am not so sure that it accurately reflects the scientific consensus on vegetation during the AHP. Jo-Jo Eumerus (talk) 12:37, 19 December 2021 (UTC)

The website it comes from is interesting but it hasn't been updated since 1998 and links to a "new version" that is dead. As far as I can tell it only lead to one scientific publications, in Internet Archaeology (2001), which says a bit about the methodology. But yeah it looks very coarse and obviously not up-to-date. – Joe (talk) 13:05, 19 December 2021 (UTC)

Looks like this is supposed to be the most recent version of the website. Jo-Jo Eumerus (talk) 10:05, 20 December 2021 (UTC)

Removed the image in the interim. Jo-Jo Eumerus (talk) 15:29, 4 January 2022 (UTC)

Regarding the length tag

I'd like to disagree with the tag Dylanvt placed here - this is a very broad scope article (c.f WP:HASTE) that can't be neatly subdivided without prohibitive amounts of work (c.f also the peer review). Jo-Jo Eumerus (talk) 17:26, 10 April 2022 (UTC)

It certainly doesn't need to be split, but I think it's worth considering. I could see the "causes" section (perhaps with the "background" section) being split off to a separate Causes of the African humid period article, and then summarized much more succinctly here. Also, is it possible to condense the bibliography? I know it doesn't affect the readable prose size, but we still have an enormous list of inline citations followed by the less enormous, and very neat, bibliography. Dylanvt (talk) 18:13, 10 April 2022 (UTC)

Well, background isn't necessarily the same thing as cause and a lot of the academic literature on the AHP is precisely about its cause, so I am kind of wary of reducing its length relative to the other sections. The problem isn't just the amount of work involved in splitting it, but also that updating 2 or more articles with one source is more work than 1 article, and there is a lot of work every year in updating (a few tens of sources to use, out of a few hundred to check).

One day, this article will hit the size limits, I believe. I don't know how many years. But in light of the amount-of-work issue I'd rather wait until it happens.

Regarding the bibliography, I am not sure how to condense it. Maybe removing parameters like ISSN? Jo-Jo Eumerus (talk) 18:32, 10 April 2022 (UTC)

I don't have anything else to say, but I hope other people will weigh on this. I have no problem with your removing the tag for now. Dylanvt (talk) 19:15, 11 April 2022 (UTC)

I've just reverted material from Population history of Egypt that contradicts this article

See [2]. Is the editor right and should that be included in this article? Note that his edits almost all seem to be from an Afro-Centric perspective, which is his right if his edits meet our policies and guidelines. Doug Weller talk 09:22, 16 April 2022 (UTC)

There is a fair amount of controversy on how quick the end of the AHP was and whether it occurred at different times in different places, but 2400BC is definitively not one major step along the way according to all the climatology papers I've seen - 4.2 ka and 5.5 ka are. I note also that none of the researchers cited appear to be climatologists. Besides, if the birth of Ancient Egypt didn't coincide with the end of the AHP, this would reinforce rather than weaken any theory of Ancient Egypt not being African, I would think, unless the inhabitants of AHP Sahara somehow don't count as African. Jo-Jo Eumerus (talk) 10:32, 16 April 2022 (UTC)

4.2 thousand years ago is 2178 BCE Dunkleosteus77 (talk) 00:28, 15 December 2022 (UTC)

The edit Doug Weller mentioned however says 2400BC. Jo-Jo Eumerus (talk) 09:15, 15 December 2022 (UTC)

@Jo-Jo Eumerus in any case, I struggle to offer gf to the editor. Doug Weller talk 14:03, 16 December 2022 (UTC)

Earth's orbit around the sun vs. axial tilt

This edit changed the former to the latter, because it's slightly factually inaccurate. As can be seen from the causes section, axial tilt was not the sole cause for the AHP. Either way, I wonder if there is a formulation that does not rely on the technical term "axial tilt". Jo-Jo Eumerus (talk) 08:22, 25 May 2023 (UTC)