Page - 1 - in Water, Energy, and Environment - A Primer

Chapter1 Waterand itsglobal context Water – a tasteless, odorless, simple chemical compound (H2O)– is themost important commodity onEarth. It is ‘key to life as we know it’ (1) and has always been a focus of human attention. In fact the pre-Socratic Greek philosopher Thales of Miletus put forward his ‘cosmological thesis’ that ‘the originating principle of nature and the nature of matter was a single material substance: water.’ (2) In modern times water has also been the focus of our search for life on other planetary bodies. 1.1 EARTH’SWATERRESOURCES The Earth is a water-rich planet. The estimated total volume of water is more than 300 million cubic miles, each cubic mile contains more than 1 trillion gallons (1012 gallons, approximately 3.78 teralitres), and water covers 71% of the Earth’s surface. Along with energy, water is one of the two ©2019TheAuthor. This isanOpenAccessbookchapter distributedunder the termsof the Creative Commons Attribution Licence (CC BY-NC-ND 4.0), which permits copying and redistribution for non-commercial purposeswith noderivatives, provided theoriginalwork is properly cited (https://creativecommons.org/licenses/by-nc-nd/4.0/). This does not affect the rights licensed or assigned from any third party in this book. The chapter is from the bookWater,Energy, andEnvironment:APrimer, AllanR.Hoffman (Author). doi: 10.2166/9781780409658_0001