The Hidden Costs of Soil Degradation: Threats to Global Food Security and Planetary Health.

Humans use soil to supply 97-99% of their calories, but the unprecedented pressure being placed on soil is now causing rapid soil degradation, including through erosion, loss of soil organic matter, acidification, contamination, salinization, and biodiversity loss. Here, we show how this degradation is causing an inherent decrease in global food productionthe loss of soil organic matter, for example, is predicted to cause a 4.3% decrease in yields for staple crops (representing calories for 640 million people) while soil erosion is projected to cause a loss in global crop production of 10% to 2050. While the adverse effects of this degradation on crop yield can often be largely masked or reversed by increased use of anthropogenic inputs such as fertilizer and irrigation, we show that some forms of soil degradation lead to permanent decreases in food production. Regardless, in all cases, we examine how both the soil degradation itself and the additional inputs required thereafter to sustain productivity result in substantial planetary harm, such as through climate change and eutrophication. It is clear that urgent action is required for ensuring both food security and planetary health, including through the development of integrated frameworks for improved policy- and decision-making.