February 23, 2012

Lack of rain led to collapse of Maya civilization

I bet that the 2012-Mayan-calendar-end-of-the-world-as-we-know-it crowd will proceed undeterred, at least until December, to ascribe preternatural powers of prediction of the far future to the Maya, just as science tells us that they failed to adjust to a relatively mild ecological shift during their own time.

From the press release:
"Our results show rather modest rainfall reductions between times when the Classic Maya Civilization flourished and its collapse – between AD 800-950. These reductions amount to only 25 to 40 per cent in annual rainfall. But they were large enough for evaporation to become dominant over rainfall, and open water availability was rapidly reduced. The data suggest that the main cause was a decrease in summer storm activity."
Science 24 February 2012:Vol. 335 no. 6071 pp. 956-959 DOI: 10.1126/science.1216629

Collapse of Classic Maya Civilization Related to Modest Reduction in Precipitation

Martín Medina-Elizalde, Eelco J. Rohling

The disintegration of the Classic Maya civilization in the Yucatán Peninsula and Central America was a complex process that occurred over an approximately 200-year interval and involved a catastrophic depopulation of the region. Although it is well established that the civilization collapse coincided with widespread episodes of drought, their nature and severity remain enigmatic. We present a quantitative analysis that offers a coherent interpretation of four of the most detailed paleoclimate records of the event. We conclude that the droughts occurring during the disintegration of the Maya civilization represented up to a 40% reduction in annual precipitation, probably due to a reduction in summer season tropical storm frequency and intensity.


Doug1 said...

Mayan civilization is generally a puzzle to me.

It's the only relatively high civilization for it's time to have occurred in a tropical region.

Some African civilizations existed in the tropical region but later than the Maya and much later in terms of contact opportunities with Eurasia. And also not as high civilizations anywhere in ssAfrica as the Maya. No independent development of written language for example. No complex and grand temple architecture. No elaborate astronomy.

They were a brutal human sacrificing on a large scale culture however. No noble savages.

terryt said...

"These reductions amount to only 25 to 40 per cent in annual rainfall".

I'd hardly describe a drop of 40% as 'only'. Especially when they add, 'large enough for evaporation to become dominant over rainfall'. Unless they had a particularly good irrigation system that would certainly be sufficient to finish any complex social structure.

By the way, hasn't that claim already often been presented as the causeof the collapse of the Mayan civilization?

eurologist said...

"It's the only relatively high civilization for it's time to have occurred in a tropical region."

How about Pakistan and India?

At any rate, the Yucatan geology is quite fascinating, with its lime stone fissures and underground rivers/ cenotes. It is easy to see that a drop in fresh water levels would be devastating. Also, there is very little top soil - such that formerly agriculturally used areas take hundreds of years to revert to anything resembling rain forest.

Andrew Oh-Willeke said...

While we're talking about tropical high civilizations don't forget Angkor Wat.

Kamal S. said...

To riff off a couple of the voices here, Mayan High civilization did not really get under way until the current era, late antiquity, from the 200's CE up. The Maya had certainly developed an increasingly complex culture in early antiquity, but by the time of their High Civilization there were already numerous tropical civilizations in Asia.

There was nothing unparalleled or unique about the Maya in being a Southern, tropics zone, civilization.

2. I have an issue with the whole idea of the noble savage and find it demeaning and more of an idealized projection of 18th and 19th century liberal European thinkers.

That said the very fact that they had a civilization should preclude them from being considered "noble savages" on a basic level; they weren't savages by definition because they were an urban civilization. Savages live in grass-huts or suchlike.

Your point, Doug1, is valid, on their extreme brutality - something often glossed over in a PC manner. But let's not forget that most civilizations in antiquity were blood thirsty and brutal by modern standards, the exact modalities of such brutality may differ, but I have yet to see an ancient civilization, in Eurasia or elsewhere, that wasn't absurdly brutal and callous by modern standards. I'd admit few civilizations evolved to the heights of the Maya, in the spectacular feats of human sacrifice their priesthood were wont to engage in.

I mean, the Romans never really had priests carving out beating hearts, flaying their victims and dancing a jig in their bleeding skin. Human sacrifice in Eurasian antiquity was a lot tamer.

I certainly concede that point.

asdf said...

Maybe southern latitude populations peak relative to northern latitude populations in warm climates and this explains the romans, mayans, muslims, europeans, and present day demographics