For many people, commemorating Earth Day is an essential activity. The Stanford Woods Institute for the Environment is hosting a free webcast on April 20 from 1:30 to 3 p.m to share reflections on progress made since the first Earth Day on April 22, 1970 and what the next 50 years may hold. Stanford alumni working in energy, sustainability, and the environment will be on hand to discuss what governments, companies, academics, and private citizens can do to help the planet. RSVP here and then go to the corners of the Monitor’sEarth coverage for environmentalist views about the history and importance of Earth Day. What inspires you to protect Earth?