I am in agreement with Aaron's explanations. Many years ago I had a friend who introduced me to new and higher levels of science, science fiction, etc. And yes, I watched NOVA before my TV was digitilized through a satellite. It is an amzing show.

The cyle of warming and cooling is a fact. It has happened before and it will happen again as long as we have an atmosphere and magnetic field - whether humans are still around or not. However, while we may not have started the process, we certainly aren't helping and are probably in fact hastening the natural process. What consequences this will have in the future no one knows. But it isn't nice to fool with Mother Nature.

One thought I had, which may be a little obtuse, is that when people are sleeping and reaching 7.83hz could be the reason why people dream, since they are tapping into the collective consciosness.

In addition to global warming/cooling cycles and the magnetic field flipping, the Earth also rotates on it's axis every so often (five hundred thousand years or so, but don't quote me on it).