The world’s main source of phosphorus fertilizer, phosphate rock, is finite and has taken millions of years to form. Phosphate rock is becoming increasingly scarce, expensive and concentrated in only a few countries. Without phosphorus, we cannot produce food. Phosphorus is as essential as water, carbon or oxygen. As an essential nutrient in fertilizers, phosphorus ensures the world’s agricultural soils are fertile, crop yields are high, farmer livelihoods are supported and ultimately that the global population can be fed. Yet it is uncertain whether the world’s main source of phosphorus will be available and accessible in the future. All farmers need phosphorus, yet Morocco alone controls three-quarters of the world’s remaining high-quality phosphate. At the same time, inefficient use of phosphorus from mine to field to fork is polluting our rivers and oceans, causing toxic algal blooms. Global action is required now to ensure we can feed ourselves and future generations.