Even though the volume of the earth's water is vast, less than 10 million of the 1,400 million cubic metres of water on the planet is of low salinity and suitable for use after applying conventional water treatment alone. The other 97.5% of the water on our planet is to be found in the oceans, where it is officially classified as seawater. Desalination provides a means of tapping this resource, and over the last 30 years, seawater desalination technology has made great strides in many arid regions of the world, such as the Middle East and the Mediterranean, and is starting to be considered viable even in cooler regions of the world not traditionally associated with water shortage (the UK for example.)