Long ago where the "grickle-grass grew" there were Truffula trees as far as the eye could see. Swomee swans flew above them, bar-ba-loot bears played in their shade, and humming-fish swam in the ponds nearby. All was green and clean, until a greedy creature called the Once-ler (the narrator of this story) arrives. The Once-ler took one look at the soft tufts of the Truffula trees and thought "Ching-ching!". Who needs trees when you could make a thneed, a product that absolutely everyone needs? The Once-ler would become rich indeed! But as it began to chop down the first Truffula tree, a strange, orange creature with a ginormous yellow mustache appeared.
"I am the Lorax. I speak for the trees!"
The lorax begged the Once-ler not to chop down the trees, but the greedy Once-ler wouldn't listen ("Business is business!"). One by one the trees disappeared. With no fruit to eat, the bar-ba-loots left, too. The swomee swans choked on the "smogulous smoke" from the thneed factory and flew away. The humming-fish couldn't swim in polluted waters. When there was nothing left of the land, the Once-ler realized its mistake...but it was too late! The only thing left to do was warn the boy who had come to visit. The Once-ler gives him a single seed from the Truffula tree, the only one left of its kind. "UNLESS" warns the Once-ler, meaning unless people take care of the earth, the same fate would happen again.
"Unless someone like you...cares a whole awful lot...nothing is going to get better...It's not." - the Lorax
The Lorax may not be as well-known as some of the other Dr. Seuss books, like Green Eggs and Ham or The Cat in the Hat (see links below), but this ecological message was ahead of its time. Now it's popular to "go green" and to reduce, reuse, and recycle to protect the environment, but back in 1971 it wasn't so cool. In fact, The Lorax was banned in California in 1989 because the forest industry felt threatened by all the bad press they were getting as a result of the book. Ironically, sometimes banned books get read more often than if they hadn't been put on the list in the first place. And for eco-friendly authors like Dr. Suess - that's a good thing!
UPDATE (3/16/12):
I just saw the The Lorax movie and it was FANTASTIC! Very cool, very colorful, and I must say it was even better than the book (no offense, Dr. Seuss!). Actor Danny Devito as the Lorax voiced the character perfectly. Betty White was funny as the fiesty grandma who was one of the only citizens of Thneedville who actually remember real trees. The fish not only hum, they sang in harmony (not to mention walked and climbed trees, but that's Dr. Suess for ya). Even if you can't find any children to take with, I say go see the Lorax movie!