"Ryan P." wrote in message
...
ecarecar wrote:


Ryan P. wrote:

ecarecar wrote:


Before you relax in you complacency, I think you should check on the rate
of change
during the "vast number of major changes in Earth's past history." I think
you will find
that never before has the rate of change been this large.

.
.
Okay, I did a bit of research. It seems that just after the end of the
last major ice age, 12,000 years ago (before modern civilzation), the global
temperature jumped by about 14 degrees (F) in just a few decades. This
article:

http://www.spacedaily.com/news/climate-04k.html

Cites several other examples of rapid climate change. Two particularly
interesting paragraphs:

""Technically, an abrupt climate change occurs when the climate system is
forced to cross some threshold, triggering a transition to a new state at a
rate determined by the climate system itself and faSter than the cause,"
according to a definition developed by the National Research Council.

Abrupt change needs a trigger, an amplifier -- some mechanism to have the
trigger affect a large area -- and a source of persistence. It turns out
lots of triggers have been identified, for example, an accumulation of
carbon dioxide in the atmosphere, as is occurring now.""

If someone claims that there was a temperature increase of "14 degrees (F) in
just a few decades"
some time in the past, they certainly can't claim it was caused by loading
the atmosphere with
carbon dioxide in just a few decades.

It is not comparable.
.
.
Speaking of which, there's disagreement on whether an increase in CO2 leads
to an increase in temperature, or if an increase in temperature leads to an
increase in CO2. Ice core samples and other evidence suggest that the planet
warmed first, and then experienced an increase in CO2 levels.

Which in no way discounts the effects of CO2 on the climate.