April brings Earth Day, celebrated on the twenty-second of the month, since 1970. The History of Earth Day states that it “is widely recognized as the largest secular observance in the world, marked by more than a billion people every year as a day of action to change human behavior and create global, national and local policy changes.” Arbor Day, now celebrated on April 28, dates back to 1872, when more than a million trees were planted in the state of Nebraska. The E...