Millions of people around the world will pause Wednesday, at least for a moment, to mark Earth Day. It's an annual event founded by people who hoped to stir activism to clean up and preserve a planet that is now home to some 8 billion humans and assorted trillions of other organisms.

Earth Day, observed every year on April 22, has grown into the world's largest environmental movement, bringing together over a billion people across 193 countries.

The theme for Earth Day 2026 is “Our Power, Our Planet”, which focuses on collective action, accelerating the transition to renewable energy and strengthening accountability for environmental damage.