April 22nd every year is World Earth Day, which is a worldwide environmental protection activity. This activity was first initiated by Gaylord Nelson and dennis hayes in the United States in 1970, and then it became more and more influential.

In 2009, the 63rd UN General Assembly decided to designate April 22nd as "Earth Day" every year. The purpose of the activity is to arouse people's awareness of caring for the earth and protecting their homes, promote the coordinated development of resource development and environmental protection, and thus improve the overall environment of the earth.

Since 1990s, China has held Earth Day on April 22nd every year.