American Forests is making it easier for your event to go green in a fast and fairly affordable way.

Sign up for its Meeting ReLeaf program and the nonprofit will plant a tree in honor of every attendee at your event as part of a U.S. forest restoration project.

Meeting ReLeaf is open to any event with at least 1,000 attendees. Smaller gatherings can make donations in $1 increments; for every $1 given, one tree is planted. There is no cost to join the program.

American Forests restores and protects urban and rural forests. Founded in 1875, it’s the oldest national nonprofit conservation organization in the country. Since 1990, it has planted more than 40 million trees in forests throughout the United States and in 38 countries. You can also go to the website and calculate your carbon footprint.