Earth Day is a global movement which happens every year on 22 April.

The first-ever Earth Day was held in 1970 in the United States, when 20 million people took to the streets to protest against big environmental issues, including oil spills, polluted rivers and air pollution.

By the end of 1970, the first Earth Day had led to the US Environmental Protection Agency being set up, and several environmental laws were brought in or strengthened.

In 1990 it became a global event. Organisers say over a billion people take part in events to mark the day in hundreds of countries all over the world.