With the approach of the annual Earth Day activities, we offer 12 'big picture' books on biodiversity, oceans, food, and waste. For April’s bookshelf we take a cue from Earth Day and step back to look at the bigger picture. It wasn’t climate change that motivated people to attend the teach-ins and protests that marked that first observance in 1970; it was pollution, the destruction of wild lands and habitats, and the consequent deaths of species. The earliest Earth Days raised awareness, led to passage of new laws, and spurred conservation. But the original problems are still with us. And now they intersect with climate change, making it impossible to address one problem without affecting the others.