First organized in 1970, Earth Day is a day set aside to remember and appreciate the Earth’s environment, and our responsibilities and roles within it. On April 22, 2020, we observe the 50th annual Earth Day, and though many things have changed for the better, environmental challenges remain. In the past 50 years, the population of the Earth has more than doubled—more than 75 percent of the people alive today were born after 1970—and the increased demand on our limited resources makes sustainable solutions even more important. Collected here are 31 images of our world from recent years, each a glimpse into some aspect of our environment, how it affects and sustains us, and how we affect it.