Human have been inhabiting earth for millions of years and for millions of years they have been exploiting the various resources that earth is replete with.
Consciously or unconsciously we have been killing the planet little by little everyday with our unbridled greed and have not, till only recently, given thought to the state of the planet which we will be leaving for our kids and the generations to come.
Earth Day has been a way of creating awareness among people about how conservation and recycling could help the regrowth of the planet even if not in a hundred years but in the next thousand years.