While we have seen an increasing number of warnings and alerts in recent years over the exploitation of the natural resources of a planet that cannot keep pace with humanity’s rates of consumption, the focus has often been on mineral resources; there has probably been less emphasis on resources that are, nonetheless, essential to life —namely, water and soils. In the context of thinking on climate change and food security, the question of the management of water resources and soils needs to be reconsidered and, as Guillaume Benoit shows here, put back at the centre of a genuinely systemic analysis. After recalling the essential elements of the water cycle and the global imbalances in the location of resources and distribution of needs, Guillaume Benoit warns of the coming intensification of water-related problems as demand for food grows and climate change makes its impact, not only in the most vulnerable regions (Africa, Asia, the Middle East etc.) but also in Europe. The question of the relationship between water, soil and agriculture thereby acquires major strategic significance, as does the issue of agroecological transition. The climate negotiations at Paris in late 2015 brought confirmation of this, emphasizing the need to stop focussing exclusively on alleviating the causes of climate-warming and to implement adaptation initiatives for reducing vulnerability to climate change. As Guillaume Benoit sees it, two trends are also revealing of ongoing developments to meet the challenges mentioned above: on the one hand, the revival of agronomy and a growing awareness of the importance of green water (which makes possible rain-fed agriculture) and of soils, and of the conservation and harvesting of water; on the other, the storage of water and the extension of irrigation. He argues that these developments should enable a new “water and soil culture” to be put in place, an agroecology acting on several levers without engendering conflict between the various possible solutions.