I wrote: That date has recently been shown by dendrochronologists to be one
in which the climate of the ancient Near East was, for some unexplained
reason, greatly altered for a short period of time.
Glen responded: Why must there be a 'cause' of a climate change? Weather is
a nonlinear
system which sometimes simple falls into attractor states which do bad or
good things to areas normally used to having the opposite? There simply
doesn't have to be a 'cause' be it meteor, or anything else.
Everything has a cause, including all weather changes and all apparent
climate cycles. However, as you point out, major changes in climate have
occurred in the past that were apparently not the result of any "catastrophic
cause." It is certainly possible that the major change in the climate of the
ancient Near East, which studies of tree ring growth indicate took place in
about 2350 BC, was caused by something far less catastrophic than a very
large meteor impact. The fact is, weather changes can be brought about by
very small causes. Meteorologists sometimes refer to "the butterfly effect"
when they explain why it is impossible for them to always accurately predict
the weather. They say a butterfly flapping its wings in Canada can start a
change in air currents which can lead to a change of the weather a couple
days later in Ohio.
But the fact is, large effects almost always have large causes, though
certainly not always catastrophic causes. Simply because there does not
appear to have been a particular "cause" to a major change in an area's
climate in the past does not mean that nothing caused that change. As I said,
everything has a cause. Though again, I agree that major changes of climate
can be brought about by something other than a catastrophic cause.
One difference between the climate changes you referred to and the one
revealed in the tree ring studies is their duration. Major changes in climate
normally last for long periods of time. This change was apparently both quite
large and quite brief, leading some to conclude it may have been caused by a
cataclysm from which the area soon recovered.
Mike
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