Civilisations were 'destroyed by climate change'

LONDON, JAN. 26. American scientists warned on Friday of `unprecedented social disruptions' that could result from global warming, after linking the collapse of societies throughout history to climate change.

There is `mounting evidence' that the demise of some civilisations was climate-driven, report Prof. Harvey Weiss of Yale University and Prof. Raymond Bradley of the University of Massachusetts, Amherst.

Scientists are now able to link the rise and fall of societies recorded in the archaeological record with evidence of the timing and magnitude of climate change held in ice cores, corals and sediments.

``We find a very precise coincidence between the abrupt climate changes and the archaeological record of collapse,'' says Prof. Weiss.

Sediments from Lake Titicaca, which straddles the border between Bolivia and Peru, reveal that South America has endured alternating periods of heavy rainfall and severe drought over the past 25,000 years.

Studies of ancient coral reefs in New Guinea show that the climate phenomenon El Nino, which disrupts rainfall patterns worldwide, is more intense these days than at any time in the past 130,000 years - possibly as a result of global warming.

Societies from the Classic Maya of the New World to the prehistoric hunting and gathering Natufians of south-west Asia were drastically affected by sudden, prolonged and intense temperature and rainfall changes which disrupted agriculture.

``These events were abrupt, involved conditions unfamiliar to the inhabitants of the time, and persisted for decades to centuries,'' say the professors in the journal Science. ``They were therefore highly disruptive, leading to societal collapse.''

The demise of the Classic Maya society in the 9th century AD coincided with the most prolonged and severe drought of the millennium.

The pyramid-constructing Old Kingdom of Egypt, the Akkadian empire of Mesopotamia, and Early Bronze civilisations of Palestine, Greece and Crete all peaked in 2300 BC, then declined when catastrophic drought and cooling struck a decade or so later.

The Late Uruk society that flourished in southern Mesopotamia in 3500 BC collapsed between 3200 and 3000 BC, again due to drought.

The professors suggest that modern societies, faced with prospects of global warming, may not be immune to social disruptions triggered by abrupt climate change.

In spite of technological change, most of the world's people will continue to be subsistence or small-scale market farmers, vulnerable to climate fluctuations.

But unlike ancient societies, who could migrate to where cultivation of crops was possible, the world is now too crowded for `habitat tracking'.

``We do, however, have distinct advantages over societies in the past because we can anticipate the future using computers,'' say the authors.

- @ Telegraph Group Limited, London, 2001

Send this article to Friends by E-Mail

Section  : International
Previous : E.U. hopes to resolve trade disputes with U.S.
Next     : Treat Singapore as equal, Goh tells neighbours