This description provides an overview of the total renewable water resources available in 2019. It states that the total renewable water resources available in 2019 is 4,000 km3. This includes surface water, groundwater, and other renewable sources of water. It is important to note that this figure is subject to
Most water in Earth's atmosphere and crust comes from saline seawater, while fresh water accounts for nearly 1% of the total. The vast bulk of the water on Earth is saline or salt water, with an average salinity of 35‰, though this varies slightly according to the amount of runoff received from surrounding land. In all, water from oceans and marginal seas, saline groundwater and water from saline closed lakes amount to over 97% of the water on Earth, though no closed lake stores a globally significant amount of water. Saline groundwater is seldom considered except when evaluating water quality in arid regions.