The water necessary to produce the food required for an expanding human population is usually discussed only as an issue of blue water for irrigation (the water we use from rivers and aquifers). This discussion neglects that most food production is from rain fed farming. This is critical not least in hunger and poverty stricken areas with rapid population growth, areas that depend not on blue water but on green water from infiltrated rain (the soil moistures used by plants and returned as vapour flow). A shift in water thinking which considers soil moisture is essential in order to find realistic and sustainable options to feed the world of tomorrow. Rain: The Neglected Resource elucidates how a shift in thinking can change how we view the world’s water resources.