Study Highlights Role of Inorganic Soil Carbon in Carbon Cycle

A study published in Science found that there is about five times more carbon in inorganic form in the top two meters of soil globally than in all terrestrial vegetation. This carbon could play a more important role in Earth’s carbon cycle than previously suspected. Scientists say that human activities such as irrigation and fertilization, as well as soil acidification from pollution, are making the soil’s inorganic carbon more mobile. Inorganic carbon lost from soils makes its way into water, where it can affect freshwater, oceans, and the atmosphere. The study’s authors say improved land practices—including some meant to sequester organic carbon—could help protect the soil’s inorganic carbon, as well. Writing on The Conversation, study authors say, “Our research shows efforts to mitigate climate change by sequestering carbon in soil must incorporate inorganic carbon as well as organic.”