What are a few novels which deal with environment as literary theme?
The Old Man and the Sea by Ernest Hemingway
A classic tale of man versus nature, The Old Man and the Sea practically captures the sea as another character in the novella.
The Grapes of Wrath by John Steinbeck
John Steinbeck addresses the Dust Bowl and the hardships of farming seasons in this Great Depression novel. The Grapes of Wrath has many passages in which the environment impacts the characters' lives or the plot.
Frankenstein by Mary Shelley
Shelley's classic monster tale actually does a beautiful job of incorporating the environment into the action of the novel as well as showing how the environment can affect the characters' actions and conflicts. The novel shifts from various interesting environments; one that particularly stands out is Dr. Frankensteins' chilling trek into the frozen lands of the North pole to catch the creature.