The surface of the Earth is covered in 70% water and approximately 98% of the total water is contained within the oceans, inaccessible as potable water. Fresh water comprises the remaining 2% of global water, which is predominantly locked up in the polar ice caps (1.6%), aquifers (0.36%) and lakes/rivers (0.036%). The small percentage of the total water that remains is contained within the atmosphere as clouds and living matter.