The celebration of ‘Earth Day’ began in the US in 1970 when Gaylord Nelson, a Democrat Senator and governor of Wisconsin, proposed April 22 as a day for Americans to speak out about the environmental crisis. See him speaking here.
Since then Earth Day has been observed not only in the US but around the world. In 2016, the United Nations chose Earth Day as the day when the historic Paris Agreement on climate change was signed into force.
2020 represents the fiftieth anniversary of Earth Day and the theme for this year is climate change. It is ironic that on the one hand events to mark the day will this year have to be digital because of the coronavirus pandemic (arguably itself a result of our cavalier and exploitative approach to the natural world) while on the other hand environmentalists may be welcoming the fact that the price of American oil has just gone negative for the first time ever.
For more information, and how to get involved, visit the Earth Day website.