While the Earth's oceans are known as five separate entities, there is really only one ocean. So, how big is it? As of 2013, it takes up 71% of the Earth, houses 99% of the biosphere, and contains some of Earth's grandest geological features. Scott Gass reminds us of the influence humans have on the ocean and the influence it has on us. Lesson by Scott Gass, animation by Sandro Katamashvili.