We humans are faced with an interesting problem: That which we think we un derstand the most-our own behavior-we probably understand the least. On the eve of a new millennium. the planet is beset by a host of problems that are. for the most part. caused by human behavior. Ironically. although it seems that the greatest impact of our behavior is on the planet and its other inhabitants. we may actually be threatening our own future the most. For example. we have caused untold harm to the air we b ...