Editor’s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, together with the solutions. Rolex’s Perpetual Planet Initiative has ...

Clouds drift past the many channels of the Palo Alto Baylands as the sun sets in this file photo. Photo by Veronica Weber. In an effort to be not only be politically correct but also environmentally ...

Artificial light, while beneficial to humans, has disrupted the natural day-night cycle and created light pollution, negatively affecting wildlife. Humans also suffer from light pollution, ...

Light pollution is causing birds around the world to sing for longer each day, prolonging their vocalizations on average by 50 minutes, according to a new study by Brent Pease and Neil Gilbert. In ...

For most of human history, darkness was a constant. The rhythms of nature, wildlife behavior, and even human sleep evolved under predictable cycles of day and night. In the past century, however, ...