Shout is a free environmental science exploration program tailored for K–12 students. It offers interactive webinars featuring renowned Smithsonian scientists, comprehensive lesson-planning materials and hands-on activities–so you can easily integrate Shout into your curriculum.
And launching soon is the Smithsonian Badges program, where students can earn digital badges by proving their knowledge of environmental topics and completing service activities in their community.
Maybe you can look at Shout for Earth Day (and beyond) activities.
Fun! And fun learning is forever learning.