What is Earth Day, when is it and what has it achieved?

The event began in 1970 in the United States, and is now marked around the world.

• Mark Poynting & Maddie Molloy
• BBC 

What is Earth Day and when is it?

Earth Day is a global event which aims to highlight the importance of protecting the environment.

It takes place every year on 22 April.

It was set up in 1970 by Gaylord Nelson, a US senator and environmentalist, and Denis Hayes, a graduate student at Harvard University.

Both had growing concerns about environmental damage in the…