Before revision: The biosphere ( from Greek βίος bíos "life" and σφαῖρα sphaira "sphere" ), also known as the ecosphere ( from Greek οἶκος oîkos "environment" and σφαῖρα ), is the worldwide sum of all ecosystems.
After revision: The biosphere ( from Greek βίος bíos "life" and σφαῖρα sphaira "sphere" ), also called the ecosphere ( ), is the worldwide sum of all ecosystems.