First, thank you for working as a substitute teacher. This is an often thankless, poorly paid duty. Even more impressive is that you share your knowledge with the students. It's not common.
I agree that the earth day nonsense is a poor choice for kindergarten students. However, we need to assign blame properly. That's the teacher's fault, not the Common Core. There is no Common Core recommended reading list, at least not from the program itself. The teacher selected that book.
If you go to the Common Core website and look for English/Kindergarten, you'll see that the standards are very common sense. Here are some samples:
CCSS.ELA-Literacy.RL.K.4 Ask and answer questions about unknown words in a text.
CCSS.ELA-Literacy.RL.K.5 Recognize common types of texts (e.g., storybooks, poems).
CCSS.ELA-Literacy.RL.K.6 With prompting and support, name the author and illustrator of a story and define the role of each in telling the story.
If you've got poor teachers in your district, don't let them off the hook by blaming Common Core.
MILLIONS of dollars were spent on a list that is **COMMON SENSE**!!!! If a common teacher must be told to do the above she should be fired immediately. Geeze! And...We wonder why we don't have a balanced budget?