Final answer:
Buck's environment in 'The Call of the Wild' changes from a comfortable life with a loving family in California to a harsh and brutal environment in the Klondike in Canada.
Step-by-step explanation:
In the beginning of Chapter 1 in 'The Call of the Wild', Buck's environment is described as a comfortable and pampered life in California. He lives with Judge Miller and enjoys a life of luxury, with plenty of food, a spacious yard, and the love and attention of his family. However, at the end of Chapter 1, Buck's environment changes drastically when he is kidnapped and sold as a sled dog. He is taken to the harsh and brutal environment of the Klondike in Canada, where he is subjected to extreme cold, hard work, and the violent behavior of the other sled dogs.