A suddenly cold climate about 5,500 years ago coincided with the
advent of ancient Chinese civilization, implying some relationship
between the two events, Chinese scientists said Monday.
About 5,500 years ago, a global climate change occurred and the
average temperature dropped by two to three degrees centigrade due
to solar activity and the orbit of the earth, geologist Liu
Dongsheng told Xinhua.
Liu, an academician of the Chinese
Academy of Sciences, said the glaciers in the western part of
China advanced forward during that period and the development of
ancient soil of the Loess Plateau in northwest China stopped, while
the cold resistant spruce prospered in regions such as today's
Beijing.
More and more archaeological discoveries seem to indicate there was
also a social change in China during that time. The poor and the
rich were differentiated in human society, and people were divided
into different social strata.
Archaeologists have found ancient settlement centers and tombs of
aristocrats in the relics of that period. Weapons became popular
funeral objects, which means that wars were common at that time.
And then castles appeared. All of these are deemed as signs of
emerging civilization, said archaeologists.
Wu
Wenxiang, a scholar with the Urban Environment Department of Peking University,
explained that the sudden change of climate caused a sharp decrease
of food and intensified the conflict between population and
resources.
As
a result, the ancient Chinese migrated from outer areas to the
center regions, from high land to low altitude places which were
more comfortable to live in, said Wu.
During the process of scrambling for resources, the concept of
private property appeared, and people's praying for favorable
weather led to the development of religion, Wu said.
But the overall environment was still suitable for human
development. The climate played an important role in human social
development, but it was not a determinative factor, said Wu.
Scientists have found that the climate change did not always push
forward the development of civilization, but sometimes caused
disasters.
The climate became remarkably cold again about 4,000 years ago,
which many foreign scholars believe is the main reason of the
collapse of the ancient civilizations in Egypt, Indus and the
Mesopotamian.
China has many legends about floods during that period. Chinese
archaeologist Yu Weichao attributed the decline of the Liangzhu and
Longshan cultures on the lower reaches of the Yangtze and Yellow
rivers to serious floods about 4,000 years ago.
"The floods turned the lower reaches of the Yangtze and Yellow
rivers, especially the Yangtze delta, into boundless water. Most of
the facilities of the formerly prosperous Longshan and Liangzhu
cultures were suddenly destroyed when their farmland was
inundated," said Yu.
He
added that production stopped, along with the development of
civilization.
Wu
Wenxiang said that when the Longshan and Liangzhu cultures were
declining, the Xia Culture was rising in central China during the
climate change, initiating China's first dynasty, Xia (about
2070-1600 BC). More studies are needed to explain why, Wu
added.
The relationship between climate change and the evolution of
civilization has drawn the attention of many scientists, who
presume that the fluctuation of climate is favorable for the
survival of the fittest.
Chinese archaeologists and scientists have begun a project to find
the origin of ancient Chinese civilization. They listed
environmental change and civilization development as an important
research subject.
(Xinhua News Agency February 11, 2003)