This place has some great science and history ideas for the third grade. These could be edited to work with a higher or lower grade. Third Grade Thinkers: Science: Earth Cycles Need to make sure its accurate to prevent misconceptions!
World Environment Day is an annual event that is aimed at being the biggest and most widely celebrated global day for positive environmental action. World Environment Day activities take place all year round but climax on 5 June every year, involving everyone from everywhere.