The Sub-tropical Desert?

We all know that all of the earliest world civilizations started at the riverbank of a desert. Another fact you might want to consider is, all of them happens to be located in the sub-tropic climated regions.

Egypt, Mesopotamia, India and China. All of them! (Assuming that we agree Greece and Persia are not as old, to be classified as member of the oldest civilization known. They're slightly younger, thus the came to form under 1000 BC. And being heavily influenced by the formers.)

So, why in the sub-tropics? Why not in the more fertile regions of the tropical climate in the equatoral area, or the colder (but more fertile) 4 season climate, like in Europe.

Alright, in the intention to simplify the understanding to the topic, allow me to divide the world in 4 climate classification:

1. The tropic rain forest. It includes, middle Africa, Indonesia and the nothern part of south America (and part of central America and the Carribic).

2. The sub-tropics, being the region between the tropical rain forest and the colder continental, 4 season climates.

3. The mild-to-cold climate. Indicated by its perfect cycle of 4 seasonal rotations. Summer, fall, winter and spring. With snow being present partial annually (not exceeding 1/2 the entire year).

4. The arctic climates. Indicated by the presence of snow and ice almost along the year, or more than 1/2 the annual time. And the day/nights exceeding 24 hours. Like those in the Skandinavia, Russia and Canada.

All set, now lets get to the question: why doesnt advanced civilizations, went to ripe in the tropical rain forests? Where sunshine is present along the year? Apparently, the human psych plays its part. Apparently life went too easy around the equator (especialy in the matter concerning the belly), so the people were too busy settling social differences existing among them. Rather than to build an advanced huge city, they were busy killing each other, instead. They stayed living in small tribes, probably because the lack of necessity in building a bigger commune in the middle of a fertile rain forest. Another factor is probably, because there are just not as much tropical regions, as of the other climate types.

Next, why wasn't advanced cities built before one milenia BC, in Europe (for example)? We have to understand that people in Europe, at that time, were the most extreme people, living in the most harsh conditions (environment) in the world. Only comperable with the Eskimos and the Mongols. The fertile regions in Europe were larger/broader compared to those in the desert, but they were not available to be used to grow food all along the year (not even for half the year). Practicaly they were only capable of growing food for ca. 3 month per year. I assume the technology at the time wasn't yet sufficient enough to support a large number of population, to rise a civilization.

So, if I am allowed to assume, the sub-tropical region was the most suitable place to set up such civilization. Why? Because they were aware, they needed to cooperate, to work on their crops. I guess, they figured out that going on a mass production was a more efficient way to meet their need for food. Rather than doing it in small groups, in the middle of the desert.

I hope i am quite convincing untill this point.

Now, allow me to extravagaze a little bit. The final mystery of the dawn of civilization lays in this: why are there so many deserts in the sub-tropical region?

Lets start with the Sahara, then the deserts in the middle easts! In southern Europe, like in Spain, Italy, parts of the Balkans and Greece. (not as dry afterall as the Sahara, but still not enough humidity to be called fertile) And than, central Asia, northen India, Tibet, the Gobi desert in China.

Lets switch to America. Mexico, Texas, Nevada, etc. But wait, we have forgoten the southerm hemisphere! the Kalahari, Australia and Chile! And maybe part of Argentine.

Did I forget something?

If I am justified to say, almost the entire sub-tropic regions are covered with deserts! Exactly the area between the tropical rain forests and the more humid, but moderately cold 4 season regions! But why? Don't you think this is strange? What is the underlaying reason to this phenomenon?

Does anyone has any theory about this? Mind to share?! Thank you for reading. Cheers

Actually you nearly get there but miseed the important bit: Sumer, Indus and Egypt all emerged in what are today desert regions but, prior to 5.5ya were much wetter. It was the shift in climate - caused, ultimately, by the steady change in Earth's tilt - that forced the peoples in those regions to work together for the common good if they were to survive. Whereas elsewhere, at that time, it was not necessary to do so.

Good post and interesting subject

1. Warmer climates allowed you to not worry as much about keeping warm
2. Disease tends to be less in such areas
3. The chain of needs: The areas that the first cities developed in were not deserts at that time. They dried up and forced people into the river basins - were to keep everyone fed agriculture was needed, and to have agriculture you needed irrigation due to the heat and lack of rain, to have irrigation you need organization and systems, and leadership and systems arose. The also developed where easy to domestic grasses grew.

As Diamond pointed out - this area just had a lot of advantages and fate & fortune smiled on them


Howdy Essan

I was typing when you were posting

They all emerged as the regions in which they appeared were undergoing dramatic climate change and becoming much drier - and thus forcing people to work together for the common good if they were to survive.

Agreed, and as I noted above too

reply to post by Essan


A perfect example of this is Roman North Africa - under the Romans, this region was extremely fertile with many thousands of miles of irrigation canals, etc. The climate shifted, the canals disappeared, agriculture went and all that is left is sandy remains (if they can be found under the dunes!).

I thought the deserts emerged ca. 10K years BC? Thats quite a long time before the 1st civilizations came to rose, don't you say?

I think u got it wrong there, at scaling the timeline.

Originally posted by Flavian
reply to post by Essan

 

A perfect example of this is Roman North Africa - under the Romans, this region was extremely fertile with many thousands of miles of irrigation canals, etc. The climate shifted, the canals disappeared, agriculture went and all that is left is sandy remains (if they can be found under the dunes!).

Southern Iraq where Sumer arose too. The land is now desert, partially do to increasing desertification but also due to salt build up from irrigation

reply to post by coyote66


Not at all, look at Leptis Magna is present day Libya. All dunes and sand today, in Roman times it was the finest city outside of Italy with great gardens and green, lush fields.

Originally posted by Flavian
reply to post by coyote66

 

Not at all, look at Leptis Magna is present day Libya. All dunes and sand today, in Roman times it was the finest city outside of Italy with great gardens and green, lush fields.

What caused this? The earth tilting on its axis, still doesnt explain the emerging deserts, IMO.

Originally posted by coyote66
I thought the deserts emerged ca. 10K years BC? Thats quite a long time before the 1st civilizations came to rose, don't you say?

A good point. The change in the climate at the end of the Ice Age (and shifts in currents and slight shifts in land masses) contributed to the deserts forming.

Deserts were around long before that time, of course. We have a lot of dinosaur material that showed some of them were living in desert or semidesert areas.

Originally posted by coyote66

Originally posted by Flavian
reply to post by coyote66

 

Not at all, look at Leptis Magna is present day Libya. All dunes and sand today, in Roman times it was the finest city outside of Italy with great gardens and green, lush fields.

What caused this? The earth tilting on its axis, still doesnt explain the emerging deserts, IMO.

Actually, you are totally correct in this and the simple answer is i don't really know.

What we do know is that past civilizations have been perfectly aware of (and afraid of) the process of desertification - written examples have survived that document this. Thinking about it, this sort of thing would probably have been attirbuted to.....#### insert past civilizations gods names here #####

Originally posted by Byrd

Originally posted by coyote66
I thought the deserts emerged ca. 10K years BC? Thats quite a long time before the 1st civilizations came to rose, don't you say?

A good point. The change in the climate at the end of the Ice Age (and shifts in currents and slight shifts in land masses) contributed to the deserts forming.

Deserts were around long before that time, of course. We have a lot of dinosaur material that showed some of them were living in desert or semidesert areas.

Yes, perhaps. But why arent there deserts in the colder regions, like in europe? Russia? Name it and, its exactly like i have described it.

Look closer in the US. The southern part are increasingly drier than the northem middle stepes. The place where the natives used to went to hunt their bisons.

Precisely at the point and line! What could have cause this?!

Maybe i need to remind, we are not textbook folks here. What i wanted to hear from u is a theory of ur own, to the matter.

A lecture from cliche schoolbooks is not exactly what i was looking for, my dear friend

reply to post by coyote66


There are deserts in the colder regions. For example, In Oregon or Washington State USA (one of those states) there is desert land. Antarctica is the largest desert on the planet.

I was led to believe that the deserts formed when all the vegetation was cut down, leaving no root systems to keep dirt intact. And deserts grow as well. The Sahara desert is growing larger every year. This is due to the large amount of sand being spread out over distances by the wind.


ETA: where the most of the Sahara is now was once a lush tropical forest. This explains the water erosion on the Great Sphynx. The desert spread onto De-forested areas.

reply to post by coyote66
I watched a vid the other day about a town being buried in sand somewhere in the north ..Russia I think or it could have been Siberia but I cant find it ..I did find this that is from the north .... www.youtube.com...

A useful link regarding the African Humid Period and subsequent desertification of N Africa/Middle East/NW India ~5.5ka

www.ncdc.noaa.gov...

And a couple of more technical papers

www.falw.vu...

www.personal.kent.edu...

Basically, around 5,500 years ago the gradual change in Earth's tilt, which in turn affects how much solar radiation reaches polar regions, reached a 'tipping point'. This then led to a southwards shift in the inter-tropical convergence zone (the area where monsoon rains occur) which meant a reduction in rainfall in N Africa, Sumeria and NW India/Pakistan compared to what these regions has experienced previously.

The 'golden age', the 'garden of Eden', was over and man, who had increased in numbers over the preceding few thousand years of 'ideal climate' in all these areas, had to learn to work and live together in towns (or migrate) in order to survive. And civilisation was born.

Originally posted by coyote66

Yes, perhaps. But why arent there deserts in the colder regions, like in europe? Russia? Name it and, its exactly like i have described it.

Deserts exist due to prevailing weather conditions - regions where for varying reasons there is little annual rainfall.

pubs.usgs.gov...

Edit: human activity, either over grazing by livestock and/or deforestation can also cause deserts to spread. These seems to have been a factor in N Africa especially.

Another factor for the rise of civilization in Sumer, Egypt, and the Indus valley is the periodic flooding they would undergo, that permitted the rise of agriculture.

Herodotus write of Egypt's flooding;
When the Nile is overflowing, it floods the Delta and the lands called Libyan and Arabian, for a distance of a journey of two days from both banks in places, and sometimes, sometimes less. I could not learn anything about its nature, neither from the priests or from anyone else. I was curious to learn why the Nile is flooding for a hundred days from the summer solstice; and when this time is passed, sinks again, and the river is low during the whole winter until the summer solstice again. (source)

By damming the waters and creating canals and planting at these times, Egypt had begun to master agriculture and had the ability to devout time and resources to other advances.

It might not be apparent today, since the Nile, and the Tigris, Euphrates and Indus river have all had their water flow so heavily restricted, but their flood plains really were the nexus from which sprang our civilizations.

reply to post by Blackmarketeer


As the rains failed, people moved to the rivers. And there a melting pot of ideas took place.