Aryan Invasion/migration Theories & Debates -2

[dhu]

thanks to farmboy for the link

<!--QuoteBegin-->QUOTE<!--QuoteEBegin-->Climate Spurred Later Indus Change
by Andrew Lawler (Science)

Climate change is not just for us moderns. Four millennia ago, a pronounced dry spell settled over much of western Asia, stressing the young Egyptian and Mesopotamian civilizations. But archaeologists have puzzled over the fact that the Indus River civilization, centered in what is now India and Pakistan, was at its height during
this time.

Now a team made up of a climate modeler, a geologist, and an archaeologist say they have solid evidence about how climate affectedIndus society. They suggest that the Indus people were able to adapt to the immediate climate change, but that resultant shifts in vegetation and landscape eventually set the culture on a slow course of decline. “How people coped varied region to region,” says Yale University archaeologist Harvey Weiss, who is not part of the effort. Weiss argues that the Akkadian empire in Mesopotamia collapsed as a result of the dramatic drought that affected societies from Ireland to China.

Previous researchers depended primarily on cores from off the coast of Pakistan and other regional data to understand climate change in the Indus region. But the team also drew on data collected between 1996 and 2001 at the ancient mound of Harappa, one of the principal cities of the Indus, and its immediate neighboring areas. By 2600 B.C.E., Harappa was a thriving urban center. <b>But starting at about 1900 B.C.E.—2 or 3 centuries after the drying period to the west—the city and nearby settlements began to lose population. By 1600 B.C.E., people appear to have abandoned their towns and moved north.</b>

The researchers fed information from the soil samples, plus data from other sources such as Arabian Sea cores, into a climate model developed by Reid Bryson of the University of Wisconsin, Madison. The resulting curve for rainfall shows that for a millennium leading up to the Indus’s peak, rainfall patterns—winter rains and the summer monsoon—remained remarkably stable. That changed dramatically in the same period that drought afflicted Mesopotamia. “They went out of kilter,” says Joseph Schuldenrein, who runs Geoarchaeology Research Associates, a Riverdale, New York–based consulting firm. Winter rains increased, but the monsoon became undependable—a pattern that continued for some 6 centuries. The result shows that the climate event did indeed affect the Indus region, says Weiss, although he has
not yet seen the detailed data.

But the rainfall change did not spark a sudden collapse in Indus settlements, notes New York University archaeologist Rita Wright, who is part of the team. “As these changes occurred, it is clear that the Harappans were experimenting with new cropping patterns” to cope, for example by planting summer crops such as millet twice a season.

In the long run, however, their adaptation apparently failed, perhaps due to a lag time in the impact of the climate change, the researchers say. Vegetation and the landscape around the area’s rivers slowly transformed, as plants vanished and rivers shifted course, according to geomorphological data the team gathered in the Harappa area. T<b>hose changes, rather than the change in rainfall per se, likely played a critical role in the move north, says Schuldenrein.</b> The Indus experience may hold a lesson for today. “Very large climatic changes can happen within a century,” points out Bryson. And the success with which societies cope may depend on local impacts—and how adaptable the locals prove to be.<!--QuoteEnd--><!--QuoteEEnd-->