Miguel de França Doria director of the Unesco intergovernmental hydrological program for latin america and the caribbean. “The first thing is to recognize the value of water and learn from it” DOCTOR IN ENVIRONMENTAL SCIENCES AND A HYDROLOGIST, HE WORKS IN A REGION WITH SOME OF THE LARGEST WATER RESERVES IN THE WORLD, BUT WITH A QUARTER OF ITS POPULATION GOING THIRSTY. A PERFECT PARADOX for examining The CHALlENGE OF ACCESS AND SHORTAGE. Why does this paradox occur? Water is not distributed homogeneously, either geographically or over time. Droughts and floods are exacerbated by the effects of global warming, which are compounded by changes in land use, expanding cities, deforestation, pollution and population growth. As the population continues to grow, we demand ever more water. And how should we deal with this problem? The mere physical and chemical existence of water is not enough to guarantee access to it. Other conditions must be met, such as human capacity to manage it, institutional capacity to ensure ap-propriate governance, as well as infrastructures to store, treat or distribute it. We need financial instruments that ensure equita-ble and sustainable access, regulatory and legal frameworks that enable it, knowledge, innovation, data, and cooperation between industries as well as between countries. In short, we need a cul-tural change. Where should we start that change? The first thing is to recognize the value of water and learn from it, which translates into research and knowledge. The institutional role is critical: we need strong institutions, at local, national and international levels, allowing us to coordinate and provide conti-nuity to all these elements. How should we adapt to climate change to ensure water security? Demand must be reduced. The problem is not using water, but using it badly, in an unsustainable manner. We must increase water efficiency: which means doing the same, or even more, but with less water. We have examples of what is possible: the amount of water used for washing clothes at home has been reduced four or five times. This must also be achieved in the in-dustrial sector and in agriculture. The other key course of action is to increase the supply, which includes important aspects such as utilizing groundwater and green infrastructure. We must re-cover ancestral irrigation and management systems and com-bine them with innovative technologies from the fourth industrial revolution. And we must not forget to protect the environmental quality of the basins, which are extremely vulnerable ecosys-tems. Infrastructure must be more resilient. Climate change has a very strong impact on surface water, aquifers and infrastructure, which must withstand the impact of hurricanes and prevent the sea from penetrating during a storm. You defend desalination as a feasible option... Yes, it is. There are many nations that make use of it, for example, Cape Verde. It is among the ten countries with the least water per capita in the world, but it is committed to desalination, human capacity building, cooperating with other countries and creating an appropriate regulatory framework to guarantee access to wa-ter for its population. Wars, migration and geopolitical tensions due to scarcity are expected. How optimistic or pessimistic are you about the future? My view is that of realistic optimism. It’s true that we face new challenges every day, but we also see people who are seeking solutions. We have to empower all those people. © UNESCO