With so much water covering its surface, Earth is sometimes referred to as the Blue Planet. There are an incredible 1.33 billion cubic kilometres of water on our planet. Oceans account for most of this water, namely 97 percent. The Pacific Ocean alone covers half the globe and is larger than all landmasses combined. Life forms existed for the longest period only in water, and no organisms can survive without water even today. Only a fraction of Earth’s water is freshwater – and yet it is the basis of all forms of life on land.