Although the Earth’s been decidedly blue for 600 million years, rising populations of phytoplankton caused by rising ...

Imagine a world where the vast oceans glimmered not in deep blue, but in brilliant green. A time when Earth’s seas, ...

For a long stretch of Earth’s history, our planet might have looked green from a distance, instead of the pale blue dot we know today. Earth’s green period, which lasted from around 3 billion ...