Maya Demise Due To Drought?

If you are interested in this topic, you can readily find other similar studies. Angkor Wat in Cambodia was architecturally hi tech (in its day), but those guys seemed to vanish suddenly. That was the original impetus for Ed Cook's MADA monsoon Asia Drought Atlas.

I don't know if there has been similar work on the Hohokam who also suddenly faded from what we now call Arizona. Would have to check.

There are several articles discussing dynastic change in China, on the thesis that they were triggered at least in part by large environmental variations. In that case, there are written records, not only paleoproxies like tree rings, cave speleothems, sediment and ice laminations and such like. Te Chinese have been writing (and storing what they wrote for an unusually long time. Still beyond me to read the stuff though

Back to Maya land, those soils have remarkably poor water-holding capacity. I have picked up wood cross sections from there (3 or 4 inches in diameter) that reveal hundreds of growth rings. Those are surely not annual rings; we know the wood grows not so slowly there. Instead they are 'storm rings'. The soil is briefly moist after rain, trees throw down some wood, and then they go back to sleep until the next rain comes. It fascinated me, but I was never in the right circumstance to study it properly and write a paper.

It may be one of those things that plant physiologists 'don't know that they don't know'.

 

Checkout "The long summer : how climate changed civilization" and "The Great Warming: Climate Change and the Rise and Fall of Civilizations" by Brian Fagan.
http://www.amazon.com/dp/product/B004JU1S76?tag=priuschatcom-20

 

I have not read Fagan's book but the information available at Amazon make it look quite interesting.There we get the impression that he relies upon Mann's paleoclimatic contruction of the medieval warm period (climate anomaly as some prefer). But also, that he demonstrates drought during the time was essentially of global extent and with substantial consequences.

 

Did the Mayans have climate change deniers too?

Their demise has long been blamed on drought, the new information that the article talks about is how small the reduction in rainfall was from the norm. It's worth reading.

 

It was drought. Saw a documentary about it a few years ago. They proved it with layers of soil dating back to the Mayan period. I think that's how they did it; it was convincing.

It shows how civilizations can get wiped out by climate change--natural or man-made.

 

perhaps they had some denied that human sacrifice could bring back a good harvest.

The mayan people didn't disappear, but the civilization ended. You have to ask even with disease and famine brought on by drought, what stopped the kingdoms. Did the population explosion cause over farming then problems like the great plains during the dust bowl during drought? Did this make people lose faith in their kings? We can at least learn that long periods of drought are normal, and plan to bring food into drought stricken areas.

 

what's the point?

 

Of researching the demise of previous civilisations? We might learn something about our own.

 

The Maya also faced an energy crisis of sorts. Plaster floor stones needed a fire of about 20 trees to create, in later constuctrion these stones got thin, because of lack of fuel source trees. The mayans had chopped down the trees and created there own energy crisis. This deforestation is now being partially blamed for exacerbating the drought.

Texans need to brace themselves for a repeat of the decade without rain that people experienced in the 50s.
Some Climatologists Worry That Texas' Mega-Drought Could Endure for Years - NYTimes.com
It may not be that bad, but farmers and water management people need to plan. It won't be nearly as bad as the 50s since there is more of a food safety net built in, but there are many more texans this time around also.

If the spanish priests hadn't burnt all the books, well 4 remain, we would have a good idea of how the mayan civilization prospered and declined. The lessons of deforestation and over farming don't require these books though.

 

Unfortunately, the article goes on to say

So next year's rainfall will either be better or worse, or possibly the same.

 

If you look at Texas in 2009 it was a drought year, 2010 had normal rainfall, 2011 was a severe drought. Looking at ENSO they can already see that 2012 will be a drought year also, and this will be particularly bad in West Texas. Its doubtful that rainfall will be as low as 2011, but because there is already stress, it may make it a worse drought. Central and eastern texas should get more rainfall but below normal. As the article says 2013 will likely be better or worse than 2012 with more of an ENSO contribution, but its too early to tell either way. If its a bad year, then texas will have 4 out of 5 years of drought. Farmers need to react and either not plant, or plant crops that can live in the drought conditions.

If crops could not be brought in from outside, texas would not be able to sustain its population. This was a problem for the Mayans, but not a problem for texas today. If anything the population could stand to be a little less nourished.

 

It's an opportunity to replace lawns with something more drought tolerant.

 

A rather strong argument could be made that (at least) for the first half of this century, water supply to population centers will be more urgent than any response needed for temperature ...excursions.

For developed countries, the largest water demand is agriculture, then thermal power plants, then industry, then domestic use...have I got that order right?

A technological breakthrough substantially lowering the energy cost of desalination would make somebody very, very rich...

(Aside) does anyone else remember a drought in southern California when lawn-watering was banned, lawns died, and at least one company did well (for a while) spray painting the dead grass green?

 

There was a drought when I lived in San Jose, CA. They requested a voluntary cutback of 15% on water usage and got a 20% response. Our reward for being good citizens was an increase in water rates because the water company wasn't making enough money on such low consumption.

 

I don't know for countries but for texas, which is different than the US, but a drought state, in 2009 with water restrictions
60% Irrigation
27% municipal (homes and offices)
7% manufacturing
3% power plants
2% Livestock
1% Mining

We use a lower percentage of coal, and natural gas and wind don't need all that much water for power generation. South Texas will soon be fracking for natural gas on a large scale and that will use a significant amount of water, which is one of the main environmental concerns as the project goes forward.

Definitely

I don't know about that but when there still was an USSR, its army spent a great deal of time painting the dead grass.

We get those things all the time. Necessary here, probably not in the bay area.