Gaylord Anton Nelson was an American politician and environmentalist from Wisconsin who served as a United States Senator and governor. He was the founder of Earth Day, which launched a new wave of environmental activism.

The first Earth Day in 1970 mobilized millions of Americans for the protection of the planet. On April 22, 1970, 20 million Americans — 10% of the U.S. population at the time — took to the streets, college campuses and hundreds of cities to protest environmental ignorance and demand a new way forward for our planet. The first Earth Day is credited with launching the modern environmental movement and is now recognized as the planet’s largest civic event.

Earth Day led to passage of landmark environmental laws in the United States, including the Clean Air, Clean Water and Endangered Species Acts. Many countries soon adopted similar laws, and in 2016, the United Nations chose Earth Day as the day to sign the Paris Climate Agreement into force.

“Despite that amazing success and decades of environmental progress, we find ourselves facing an even more dire, almost existential, set of global environmental challenges, from loss of biodiversity to climate change to plastic pollution, that call for action at all levels of government,” said Denis Hayes, the organizer of the first Earth Day in 1970 and Earth Day Network’s Board Chair Emeritus.

“Progress has slowed, climate change impacts grow, and our adversaries have become better financed,” said Earth Day Network president Kathleen Rogers. “We find ourselves today in a world facing global threats that demand a unified global response. For Earth Day 2020, we will build a new generation of environmentalist activists, engaging millions of people worldwide.”