Celebrated on 04/22/2026
Earth Day was first celebrated on April 22, 1970, and is now observed by over 1 billion people in more than 190 countries, making it the largest secular observance in the world. The date was chosen to fall between Spring Break and final exams to maximize student participation.
Earth Day was founded by U.S. Senator Gaylord Nelson of Wisconsin, who was inspired by the anti-war teach-ins of the 1960s to create a national day of environmental education and activism. After the devastating 1969 oil spill in Santa Barbara, California, Nelson announced the idea for a "national teach-in on the environment" in a speech in Seattle in September 1969. He recruited Denis Hayes, a young activist, to organize the event, and they chose April 22, 1970, as the date. The first Earth Day mobilized 20 million Americans, leading to the creation of the U.S. Environmental Protection Agency and the passage of landmark laws like the Clean Air Act, Clean Water Act, and Endangered Species Act.
In 1990, Earth Day went global, with 200 million participants in 141 countries, boosting recycling efforts worldwide and paving the way for the 1992 United Nations Earth Summit. Today, Earth Day is coordinated globally by the Earth Day Network, which engages over 1 billion people annually through events, policy advocacy, and digital campaigns. Modern celebrations include tree planting, community clean-ups, climate marches, and educational programs focusing on climate change, plastic pollution, and sustainable living. Earth Day 2020 marked its 50th anniversary with a global digital event due to the COVID-19 pandemic.
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