reply to post by jokei
If you read the article, it says that this climate that we have become accustomed to is an anomaly given the earth's climate history. The evidence
more than suggests that the "normal" condition of the planet is without permanent ice covered areas.
To me, this strongly suggests that not only is the global warming trend a part of a natural cycle, but that plants and animals that existed prior to
the planet's cooling can and do survive what, if humans had been around 14 million years ago, would have been declared a calamitous climate
change.
"If we can understand how we got into this relatively cold climate phase, then that can help predict how global warming might push us back
out of this phase. For the vast majority of Earth history there was no permanent ice like is common today at the poles and even the tropics at high
elevation. There's been a progressive cooling going on for 50 million years to get us into this permanent-ice mode; the formation of a permanent ice
sheet on Antarctica plays a big role in that cooling.
[...]
"To be able to identify living species amongst the fossils is phenomenal. To think that modern counterparts have survived 14 million years on Earth
without any significant changes in the details of their appearances is striking. It must mean that these organisms are so well-adapted to their
habitats that in spite of repeated climate changes and isolation of populations for millions of years they have not become extinct but have
survived."
What caused the big freeze is unknown though theories abound and include phenomena as different as the levels of carbon dioxide in the atmosphere and
tectonic shifts that affected ocean circulation.
tinyurl.com...
[edit on 2008/8/15 by GradyPhilpott]
