Google Doodle marked the 46th anniversary of Earth Day which began in 1970 in response to a 1969 massive oil spill near Santa Barbara, California.

Earth Day was founded by US Senator Gaylord Nelson as an environmental teach-in first held on April 22, 1970.

The theme of Earth Day 2016 is "Trees for the Earth". 

It is now coordinated globally by the Earth Day Network and celebrated in more than 193 countries each year.