Climate activists hold a rally to protest the use of fossil fuels on Earth Day at Freedom Plaza, April 22, 2023, in Washington. Credit: AP Photo/Carolyn Kaster, File Millions of people around the world will pause on Monday, 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. Here are answers to some common questions about E...