This Thursday, April 22, marks the fortieth anniversary of Earth Day. Forty years after the first Earth Day, the world is in greater peril than ever, but while climate change is the greatest challenge of our time, perhaps of all-time, it also presents an unprecedented opportunity to build a sustainable, clean energy economy.

This video from Greenpeace makes clear what’s at stake and why it’s critical to act now and get involved in whatever way you can.

Tomorrow I’ll be posting my attempt at a comprehensive guide to events, actions and groups you can join this Thursday in the fight to save the planet.