Happy Earth Day!

Earth Day, which began in 1970, was the inspiration of Gaylord Nelson, who at the time was a U.S. Senator from Wisconsin. Nelson had been deeply affected by the damage caused by a massive oil spill off the California coast the year before and believed he could harness the same energies he saw in the anti-Vietnam War student movement to shine a spotlight on environmental issues. Thanks to Nelson (and the efforts of many others, including Denis Hayes, who coordinated the first Earth Day and several others), such landmark legislation as the Clean Air, Clean Water, and Endangered Species Acts came into being, as did the U.S. Environmental Protection Agency.

Today, Earth Day is a global phenomenon and this year there are events from tree-planting in Armenia to a conference featuring astrophysicist Neil deGrasse Tyson in Madison, Wisconsin, in honor of the occasion. This year’s theme is “It’s Our Turn to Lead,” so get out today and join with others to raise awareness for environmental issues, or just grab some friends and clean up the trash in your neighborhood.

Here’s a comprehensive list of Earth Day activities happening around the world.