Fungal networks move 4 billion tons of CO2 into soil annually, new global map shows | carboncredit.io

Scientists have mapped the global extent of arbuscular mycorrhizal fungi for the first time, revealing an underground network stretching 68 quadrillion miles. These fungal highways move an estimated 4 billion tons of carbon dioxide equivalent into soils each year, roughly 11% of human-caused emissions. The new study in Science uses data from 16,000 soil cores and machine learning to predict network density worldwide. Grasslands hold about 40% of this fungal infrastructure, but they are being converted to cropland four times faster than forests. Agricultural soils show roughly 50% lower network density, which could reduce carbon storage and nutrient cycling. The researchers argue that fungi have been overlooked in climate and conservation planning and that these maps give policymakers a new tool for protecting underground ecosystems that play a major role in carbon sequestration.