I heard something the other day which gave me pause, but can't find reference to it now. Blast.
Here's the concept: The Mayan Civilization grew rapidly from the 5th century A.D. From Jarod Diamond's Collapse, focusing on just one section of the sprawling empire:
I'll now suggest that rainforests are better able to sequester carbon that previously thought, especially when sparsely occupied, and that the forests would have, no doubt, retaken the former bustling metropolises and supporting farmland the shrinking number of Maya would abandon.
With me so far? Okay. Now let's consider that carbon gases take time, once released from a felled tree, to affect climate. Isn't it weird how the growth and peak of Mayan civilization preceded by one or two hundred years the Medieval Warm Period, a warm period from roughly 800-1300?
It gets more interesting once we consider that even more time would be needed for a forest retaking its former cultivated land to reabsorb those carbon gases released hundreds of years earlier. Once re-sequestered in the forest, though, whole weather patterns would be affected. Here's a few more quotes from Collapse:
Interesting, eh? Purely speculative, but interesting nonetheless.
Addendum, July 26, 2009: Perhaps their growth led to a positive feedback loop that allowed for their further expansion. Still just speculation.
X-Posted, just for chuckles, to
boiling_frog.
Here's the concept: The Mayan Civilization grew rapidly from the 5th century A.D. From Jarod Diamond's Collapse, focusing on just one section of the sprawling empire:
As judged by numbers of house sites, population growth in the Copán Valley rose steeply from the 5th century up to a peak estimated at around 27,000 people at A.D. 750-900. Construction of royal monuments glorifying kings was especially massive between A.D. 650 and 750. After A.D. 700, nobles other than kings also got into the act and began erecting their own palaces . . . .
. . . the last that we hear from any Copán king is A.D. 822. . . the royal palace was burned around A.D. 850. However, (various pieces of evidence) suggest that some nobles managed to carry on with their lifestyle after the king's downfall, until around A.D. 975.
. . . The estimated population in the year A.D. 950 was still around 15,000, or 54% of the peak population of 27,000. That population continued to dwindle, until there are no more signs of anyone in the Copán Valley by around A.D. 1250. The reappearance of pollen from forest trees thereafter provides independent evidence that the valley became virtually empty of people, and that the forests could at last begin to recover.
(Diamond, Collapse, Penguin Books, 2005, pp. 168-170, emphasis mine.)
I'll now suggest that rainforests are better able to sequester carbon that previously thought, especially when sparsely occupied, and that the forests would have, no doubt, retaken the former bustling metropolises and supporting farmland the shrinking number of Maya would abandon.
With me so far? Okay. Now let's consider that carbon gases take time, once released from a felled tree, to affect climate. Isn't it weird how the growth and peak of Mayan civilization preceded by one or two hundred years the Medieval Warm Period, a warm period from roughly 800-1300?
It gets more interesting once we consider that even more time would be needed for a forest retaking its former cultivated land to reabsorb those carbon gases released hundreds of years earlier. Once re-sequestered in the forest, though, whole weather patterns would be affected. Here's a few more quotes from Collapse:
In the U.S. Southwest . . . cultures that underwent regional collapses, drastic reorganizations, or abandonments at different locations and different times include Mibres around A.D. 1130; Chaco Canyon, North Black Mesa, and the Virgin Anasazi in the middle or late 12th century; around 1300, Mesa Verde and the Kayenta Anasazi; Mogollon around 1400; and possibly as late as the 15th century, Hohokam. . . . (Ibid, p. 137.)
Between A.D. 800 and 1300, ice cores tell us that the climate in Greenland was relatively mild, similar to Greenland's weather today or even slightly warmer. Thus, the (Viking) Norse reached Greenland during a period good for growing hay and pasturing animals. . . . Around 1300, though, the climate in the North Atlantic began to get cooler and more variable from year to year, ushering in a cold period termed the Little Ice Age that lasted into the 1800s. By around 1420, the Little Ice Age was in full swing, and the increased summer drift ice between Greenland, Iceland, and Norway ended ship communication between the Greenland Norse and the outside world. Those cold conditions . . . were bad news for the Norse, who depended on growing hay. (The) onset of the Little Ice Age was a factor behind the demise of the Greenland Norse. (Ibid, pp. 219-220.)(All emphasis mine.)
Interesting, eh? Purely speculative, but interesting nonetheless.
Addendum, July 26, 2009: Perhaps their growth led to a positive feedback loop that allowed for their further expansion. Still just speculation.
X-Posted, just for chuckles, to
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