More Unasked Global Warming Questions

The planet has undergone periods of climate change and widespread glaciation before. When did they occur, and what did the associated temperature cycles look like?

This graph shows the last 540 millions years worth, and clearly the previous cycles had nothing to do with the activities of humanity:

http://en.wikipedia.org/wiki/Timeline_of_glaciation

So, while we might be able to slow down the human contribution to the latest cycle, what makes us think that the other reason(s) for these cycles no longer exist?

And why does the O16/O18 ratio show that we're currently in a "cold" part of the latest cycle? I thought we were in a global warming heat wave.

I suggest everyone study Burt Rutan's climate change presentation before we allow Obama ad-Dajjal and the rest of the climate change loonies to destroy the world's economy with their wacky climate change "conspiracy-like theories":

http://rps3.com/Files/AGW/EngrCritique.AGW-Science.v4.3.pdf