David Suzuki is co-author of "Tree: A Life Story", (augmented by illustrations from Robert Bateman) which spans the 700-year life cycle of a Douglas fir. How the survival of the tree is interlinked with a myriad of plant and animal life, is a metaphor for humans, whose lives are also part of a diverse ecosystem. Suzuki believes that one of the root causes of environmental problems is that there is often a disconnect between human behaviour and its outcomes. He also mentions the Nature Challenge and gives tips on some effective ways to conserve nature. (Originally aired November 2004)