The direct per capita availability of freshwater resources decreases as the world population continues its growth. This fact threatens the well-being and subsequently the survival of humanity as a whole. In this article, the North-South approach is used to raise certain questions on the significance of scarcity. Indeed, the issue of water for tourists might seem far removed from water scarcities for poor people in the South. If we assume a technological trajectory of decreased monetary costs, decreased energy costs per cubic metre, and moreover increased share of renewable energies in desalination (a kind of win-win-win scenario), does this mean that water for urban use of poor people in the world will cease to be a problem? Will not the energy costs remain too high? An approach based on the "basic needs" scenario is relevant to address these questions. The Canary Island of Lanzarote (Spain) and the city of Laayoune, (Moroccan Sahara) are taken as explanatory case studies.