On Earth Day this year, what I’m thinking about is not the beauty of our planet, or the fragility of it, but how quickly it's changing. I’m just back from a two-month-long research trip to Antarctica, where I came face-to-face with Thwaites glacier (AKA The Doomsday Glacier), which is one of the most consequential tipping points in our climate system. What I learned in Antarctica is not just how dramatically humans are reshaping the world by continuing to burn fossil fuels, but also how quickly those changes are happening, even in remote places like Antarctica. Below are a few stories that highlight those changes, as well as a few stories that discuss what we humans might do about them, should we decide to take dramatic action. What’s at stake is not the Earth—the planet has been through much, much worse in the last 4 billion years. It’s civilization that’s on the line.