The book is great for classroom use since it contains activities (such as making volcanoes, windmills, and rain gauges), a quiz, a glossary, and additional resources. The author also has parent and teacher notes to reference the various scientific elements included; ie Earth, weather, climate, etc. This resource, in addition, can teach "language arts curricula in the elementary grades" with suggested writing, language and art activities.
Probably more geared for the younger grades as it is set to background music, this video teaches about the beauty of life on earth. The link contains information about how and why we should keep our planet in even better shape for the future. I would follow this up with an activity or coloring sheet, such as creating their own family tree (families could even be asked to send pictures in advance.)
Any Earth Day discussion could be included in your science topic of the solar system. Let your students know more about our "3rd Rock from the Sun" with this short video on recycling while talking about why our planet is the only one we have so it must be preserved. YouTube indicates the appropriate age range is K-4 with a 6-minute length. Knowing that every small effort on Earth to collect paper, aluminum, and glass for re-use can teach kids about their impact on our huge universe!
Of course, there are several books to select for Earth Day reading. But I immediately recognized "The Lorax" as Dr. Seuss is incredibly popular with lower grade children. Even for grades 3-5, the book can be enjoyed perhaps in its movie format. This link includes Q&A for paired discussion as well as an art project. Children who have heard the story before may be more familiar, so be sure to stress the theme of how humans create pollution and it has a negative affect on our environment.
This link is amazing for interactive ideas to use both in and out of the classroom. Since Earth Day happens in spring, it suggests outdoor activities like litter pickup, a nature walk, and flower or seed planting. As we know, children who are engaged learn the most so this lesson is an ideal opportunity to experience Earth outside of school. The online page layout is easy to follow since its broken down into 3 methods of teaching that day with corresponding ideas.
Great link for WHY it is so important for kids to "think ahead" into the future about saving earth NOW, not just once a year either but every day making an effort to save our environment for their kids as well. It is a BIG job but one that should be stressed even LITTLE helpers can do. Children may like hearing that they can go home and tell older family members what they should do to be good citizens too.