Earth Day is an annual event on 22 April to demonstrate support for environmental protection. First held on 22 April 1970, it now includes a wide range of events coordinated globally by www.earthday.org including 1 billion people in more than 193 countries.
Earth Day: The Official Site | EARTHDAY.ORG
Visit the Earth Day education resource library for ideas on how your school can get involved: Education Resource Library | Earth Day