Learn more about the Phosphorus Cycle

This video shows a graphical illustration of the phosphorus cycle.

In pre-industrial times, weathering of rocks released, on average, 0.003 petagrams of phosphorus annually. This phosphorus served as a natural fertilizer, making it (theoretically) possible to feed a global population of less than 1 billion people. Phosphorus is carried by rivers from the land surface to the oceans. It is ultimately buried in sediments and – after millions of years – returns to the Earth’s surface as new mountains are formed.

In 2019 (peak phosphorus), humans mined 0.02 petagrams of phosphorus from known reserves totaling 6 petagrams. This was to feed a global population of more than 7 billion people. Dividing 6 by 0.02 gives 300 years. This is approximately how much time remains before we have used up all known reserves of phosphorus.