Could human waste revolutionize sustainable farming worldwide?

Human waste could soon play a bigger role in farming as a sustainable alternative to synthetic fertilizers. Research confirms that treated urine and composted faeces provide essential nutrients like nitrogen, phosphorus, and potassium. At least ten countries, including Sweden, Germany, and the US, have already introduced regulations or pilot projects to explore this approach. Using human waste as fertilizer is not a new idea. Ancient civilisations relied on it, and the practice continues today in parts of Asia, Africa, and Latin America. However, modern sewage systems dilute waste, making large-scale collection difficult.

Synthetic fertilizers currently dominate global agriculture, but their production is energy-heavy and emits significant CO₂. Meanwhile, phosphate—a key fertilizer ingredient—is a finite resource, classified by the EU as a 'critical raw material.' Studies suggest that extracting nutrients from wastewater could meet 15% to 50% of agricultural phosphorus needs. Human excrement contains around 40 million tons of nitrogen yearly, enough to cover roughly 20% of global fertilizer demand. Despite the benefits, the EU currently bans the practice over hygiene concerns, though scientific research is allowed. The biggest challenge may not be technical but psychological—overcoming the public's discomfort with the idea.

If widely adopted, treated human waste could reduce reliance on synthetic fertilizers and cut emissions. Countries with existing regulations show the approach is feasible, but scaling it up will require better collection methods and public acceptance. The potential benefits for sustainability and food security remain significant.