March 21, 2008

Genghis Khan, Vikings, and the Maya

A new book says we should blame weather rather than warfare for the collapse of Amerindian civilizations.

Climate Change?  Been There, Done ThatLonger summers and milder winters in Europe, especially stable from 1100 to 1300, allowed Norse explorers to range as far as Greenland and Labrador. At the same time a population boom in the rest of Europe led to radical deforestation, as trees were cleared to create farmland. By the end of the Medieval Warm Period half the forests that covered four-fifths of Western and Central Europe in A.D. 500 had disappeared.

Across vast swaths of the globe, however, severe, persistent droughts lasted not just for years but for generations. The Sierras of modern-day California experienced the severest droughts of the past 4,000 to 7,000 years. Acorn trees died, and along with them peoples largely dependent on acorns for food. Although data remain sketchy, it seems probable that extended droughts dried up pastureland on the Central Asian steppe, propelling the armies of Genghis Khan westward.

In the southern Yucatan arid conditions proved too much for the elaborate reservoirs, called “water mountains,” that the Maya used to irrigate their fields. Mr. Fagan permits himself an ominous aside: “The analogies to modern-day California, with its aqueducts for water-hungry Los Angeles, or to cities such as Tucson, Ariz., with its shrinking aquifers and falling water table, are irresistible.”
The implications for modern society:The causes of the Medieval Warm Period remain unclear, and there is debate over what the actual temperatures were. Mr. Fagan draws one unambiguous conclusion from the evidence, however, in a final chapter on the present-day implications of the great warming of a thousand years ago. Drought is the great enemy, “the silent and insidious killer associated with global warming,” he writes.

Population density has placed enormous pressure on increasingly scarce water resources. As a result modern droughts, brought on by El Niño events, have taken an enormous toll in lives and wreaked measureless economic devastation. Prepare for worse.

“Judging from the arid cycles of a thousand years ago, the droughts of a warmer future will become more prolonged and harsher,” Mr. Fagan writes. “Even without greenhouse gases, the effects of prolonged droughts would be far more catastrophic today than they were even a century ago.”

For a spark of hope Mr. Fagan offers the example of Chimor, a kingdom in coastal Peru tormented by El Niño flooding and severe droughts throughout the Medieval Warm Period. The Chimu people thrived nonetheless by diversifying their food supply and protecting their scarce water resources. In a historically arid region with uncertain food supplies, they successfully tapped their centuries of experience with irrigation, soil conservation and water management. Look no further for a global-warming role model.
Comment:  So a single climatological phenomenon may have been responsible for the rise of Genghis Khan, the Viking exploration of America, and the fall of the Maya, "Anasazi," and Khmer civilizations? Fascinating.

This tends to contradict the theories that say the Maya and Anasazi civilizations collapsed because of warfare. It's possible the droughts aggravated or even caused tensions that wouldn't have been fatal otherwise.

The Great Warming suggests the need for a more multicultural perspective. We need to learn from cultures such as the Chimu and Hopi about living within our means and conserving our resources. We should be imposing the actual costs of land development, water and energy usage, and environmental pollution so they don't overwhelm the ecosphere and lead to the collapse of our civilization.

For more on the subject, see Ecological Indian Talk.

6 comments:

writerfella said...

Writerfella here --
Interglacial periods of warming are not as simple as once believed but also more are the norm than once they were believed. El Ninos and La Ninas, increases in 'greenhouse gases, mass atmospheric pollution, and even variations in solar output have been joined for our consideration by increased cosmic radiation, varying internal heat releases from within the earth itself, and falling levels of magnetic field outputs that enwrap the planet as a protective shield. Add in that there actually has been an accidentally-created umbrella of reflective matter placed in the upper atmosphere by thousands of high-flying aircraft, and one realizes that 'global warming' would have been much worse without it. For a time after 9/11, when almost all air traffic was ceased over North America, that reflective umbrella of water vapor and hydrocarbons went unreplenished and actually began to thin. And scientists observed that the undimmed sun began to heat the environment of this continent at an alarming rate. Only when air traffic returned to normal did such increased heating fall back to its former levels. While industrial and fossil fuel air pollution may be aggravating an already existing cycle of interglacial warming, another form of air pollution instead was holding it back, reflecting some of the sunlight that would have reached the earth otherwise. Many in the public interpret 'global warming' to mean that the earth's surface is getting hotter, whereas the term really means that the atmosphere retains more energy from its sunlit hours than it can re-radiate into space during its nightside hours. And more energy means that winds and storms are more powerful, with vast shifts in their former patterns, resulting in droughts in formerly fertile areas and flooding in formerly arid areas, along with depletion of the polar ice fields. As well, the planet's temperature equalization mechanism is interrupted and ocean currents are changed so that warmer waters enable cold crystallized methane to decompose and escape from the depths into the atmosphere. Methane is several times more powerful a hydrocarbon 'greenhouse gas' than carbon dioxide or sulfur dioxide or fluorocarbons ever could be. Therefore, collapse of civilizations very soon will be the least of the world's worries, as mass worldwide extinctions are known to have been caused by singular, much smaller factors...
All Best
Russ Bates
'writerfella'

dmarks said...

"accidentally-created umbrella of reflective matter placed in the upper atmosphere by thousands of high-flying aircraft"

Contrail "Science" is as good as the "Science" that led explorers to think that they would fall off the edge of the earth rather than find the Americas. In other words. all bogus.

writerfella said...

Writerfella here --
Writerfella once toured Ports O'Call Village in Long Beach with Harlan Ellison and other friends, and Harlan picked up a set of four Spanish galleons made of cut copper sheeting. He asked writerfella what they were, and writerfella replied, "Ah, the four ships of Columbus!" Harlan asked, "FOUR? How's that?" And writerfella said, "Yes, the Nina, the Pinta, the Santa Maria, and the Santa Christina." "Well, what happened to the Santa Christina?" "Oh, it fell over the edge..."
DMarks may have yet another plaint, and it will be that the NOVA series on PBS did an entire documentary episode last September called "Dimming The Sun" on the phenomena writerfella reported. THINK of DMarks' tax monies that went to pay for such a "bogus" scientific report! Why, DMarks should sue! And then again maybe DMarks had better stay out of the sun, as well...
All Best
Russ Bates
'writerfella'

Rob said...

Thanks for that l-o-ong comment, Russ. But I thought you disliked long comments. Or do you dislike only my long comments?

You already told us that joke in The Columbus Attitude. FYI, Ports O' Call is still in San Pedro, not Long Beach. Trust me on this one: I was born in Long Beach and raised in Palos Verdes, next to San Pedro. My brother now lives in San Pedro, just a few miles from Ports O' Call.

Here's a source for contrail science:

http://contrailscience.com/

The Science and Pseudoscience of Contrails and Chemtrails

writerfella said...

Writerfella here --
L-o-o-o-n-n-g comments justify themselves, if what is being stated IS NOT AN ITERATION OR DOES NOT ITERATE. This is not about Iraq. This is about writing. It has rules...
All Best
Russ Bates
'writerfella'

Rob said...

I make the rules here. I justify my comments because this blog exists so I can say whatever I want about the intersection of Native America and pop culture. If you don't like it, you can always leave.