As the climate crisis becomes ever more serious, each Earth Day that comes along takes on extra significance. Established in 1970 in the US, the annual event—which is celebrating its 55th anniversary this year—brings together millions of people from around the world in support of the environment, highlighting the urgent action we need to take to save our planet.

Earth Day 2025 comes as the United Nations’s World Meteorological Organization found that the world experienced more than 150 “unprecedented” climate disasters in 2024. These included six tropical cyclones in the Philippines; blistering heatwaves across Europe, east Asia and the Middle East; and severe flooding in countries like Italy, Brazil and Senegal. At the same time, 2024 was the hottest year on record—with temperatures exceeding 1.5 degrees Celsius compared to pre-industrial levels for the first time.

Despite the countless other challenges the world is facing right now, it’s crucial that the climate crisis isn’t forgotten. Below, here’s everything you need to know about Earth Day 2025.

The first Earth Day held in 1970 in New York.Photo: Getty Images

What is Earth Day?

Marked by millions around the world, Earth Day is an annual event designed to shine a light on the serious environmental problems we’re facing, from the climate crisis to air pollution and deforestation. Every year we see organizations around the world launch dedicated campaigns to call for more action to protect our planet, while many companies also use the day to launch new eco-minded initiatives.

When is Earth Day 2024?

Earth Day takes place on April 22 every year, but the entire month of April (sometimes called Earth Month)—and especially the week running up to Earth Day (sometimes called Earth Week)—is a time when environmental issues take center stage.

Why is Earth Day on April 22?

Earth Day was the brainchild of US senator and environmentalist Gaylord Nelson, following a 1969 oil spill in Santa Barbara, California. He came up with the idea of having college teach-ins to highlight the importance of clean air and water, with April 22 chosen as a convenient date between Spring Break and finals.

Organizers decided to name the date Earth Day, with the first event in 1970 leading to an astonishing 20 million people across the US taking to the streets—around 10 percent of the country’s population at the time. The event undoubtedly had a major impact, with President Richard Nixon creating the Environmental Protection Agency just months later in December 1970, as well as signing the Clean Air Act.

Earth Day later became an international campaign in 1990, when environmental activists asked one of the original organizers, Denis Hayes, to help create another event to spotlight the ecological challenges facing our planet.