On Nov 4, 5:39*pm, Sam Wormley wrote:
The Dependable Warmer

During the middle of the Eocene, about 40 million years ago, a transient
warming event interrupted the long-term cooling trend that had been in
progress for the previous 10 million years.
Sufficient evidence is around that the Eocene warming event
occurred, and was caused by an increase in carbon dioxide in the
atmosphere. However, that was a very big change in carbon dioxide
levels. There is no evidence that the man-made generation of carbon
dioxide even nearly compares to that.
The Eocene was a different world than today. No one is sure what
triggered the increase in carbon dioxide during the Eocene Warming
Event (EWE). The initial warming may not have been due to carbon
dioxide. The increase in carbon dioxide could have been caused by
something else. Remember that the world had been cleansed only about
10-20 MY before the EWE. The world was still out of balance due to the
KT extinction. The EWE may have been a type of "reset" on the earths
climate.
The EWE is not associated with a global extinction. The fossils show
that tropical plants predominated during the EWE. When the EWE ended,
the cold weather plants came back. Very few plants went extinct. The
cold weather plants seem to have dominated previous to the EWE, hid
some where during the EWE, and came back after. Although some animals
did go extinct, most animals recovered. This despite a 6 C increase in
global temperatures. Thus, the argument could be made that man-made
warming, even if real, may not be as significant as feared.
On the other hand, the EWE does show that large climatic changes
are possible. The EWE probably wasn't fun for cold weather organisms
while it was going on. The number of cold weather plants decreased. A
cold weather few survivors apparently lived where fossilization wasn't
common. This probably means in areas where erosion was very large.
Some animal species did go extinct.
For paleontology fans, the EWE marked the border where large
mammals became dominant. After the Creteceous-Tertiary extinction
(KTE), most animals including mammals were very small. The dinosaurs
were gone, but most everything else that was large also died The KTE
had wiped out all the large animals. Large species become common after
the Eocene. So the EWE may have in the long run (millions of years)
been "good" for mammals and other large animals. However, I don't
think such an event would be good for the human species today.