Earth Day, April 22, is an annual event to demonstrate support for environmental protection. First observed in 1970, it is now coordinated by EarthDay.org and recognized by the United Nations in over 190 countries.
US Senator Gaylord Nelson conceived the first Earth Day in 1969 following the Santa Barbara oil spill. The first event on April 22, 1970 drew 20 million Americans — about 10% of the population — and is credited with launching the US Environmental Protection Agency and the Clean Air Act. Earth Day went global in 1990 and is now coordinated by EarthDay.org.
Tree-planting, beach cleanups, community gardening days, environmental education events, climate change marches. Many cities car-free for the day. Schools host environmental projects.
Not a public holiday in any country, but widely observed by schools, NGOs, and businesses with sustainability themes.