It's been called the boldest experiment in Digital Publishing to date.
The Reversing of Earth's Magnetic Poles

The Reversal of Earth's Magnetic Poles
David Suzuki - Nature of things - CBC TV - 1 hr

YouTube version; not of the best quality, but viewable everywhere.

The original on the CBC site may or may not work where you are and is available on the site for who knows how long.

Part 1

Part 2

Part 3

Part 4