In what year was the first Earth Day celebrated? 1970 How many people celebrated the first Earth Day? 20 million In what year did Earth Day become an official UN event? 2009 How many people celebrated the first global Earth Day? 200 million How many people celebrate International Mother Earth Day now? 1 billion In what year did Earth Day become a global event? 1990 https://339efcb25eb75e967b0d-ff8eeadd950d51fd1fc939dca75b3973.ssl.cf1.rackcdn.com/assets_default.swf