Glaciation Period On Its Way

From "Science Matters" by Robert M. Hazen and James Trefil. It's an excellent, readable, apolitical journey into the heart of science. It's certainly perfect for a refresher. It's a book that could have been written by your science teacher. Nothing but science.

Of course, they lose me in all those sub-atomic particles and quantum parts, but hey, I'm slow that way. Given the debate surronding global warming, I found this part interesting in the chapter discussing 'Earth Cycles' and ice caps and glaciers in particular:

"The most recent ice age was in full swing 20 000 years ago, when glaciers extended as far south as Chicago. Today we live in what geologists call an interglacial, a term we find chilling in every sense of the world. On a shorter time scale, chance events also affect the glacial cycle. Major volcanoes can spew dark matter into the atmosphere, blocking sunlight and cooling the planet for a year or two, which creates brief periods of growing glaciers. Increased atmospheric concentrations of carbon dioxide and other greenhouse gases, whether man-made or natural, may have the opposite effect. The best prediction available now is what we are (or should be) heading into another period glaciation, although the advent of global warming by the greenhouse effect may introduce a temporary glitch in the grand cycle of freezing and melting."

There you go.