Biochar from human waste could solve global fertiliser shortages, study finds

About a quarter of global greenhouse gas emissions come from agriculture, the IPCC says. Photograph: Alex McGregor/Alamy

Charcoal made from human waste could help solve fertiliser shortages as well as reduce pollution and energy use, a study has found.

Biochar is a form of charcoal made from organic matter treated at high heat, which is often used on farming soil as a fertiliser. The process also removes carbon from the atmosphere, making it a useful carbon sink.