The Society for the Protection of Underground Networks (SPUN) has published the first global map of mycorrhizal networks: vast underground fungal filaments that connect with plant roots, exchange nutrients for plant-made carbon, and may channel a significant share of carbon into soils. The map estimates roughly 110 quadrillion kilometers of these networks worldwide and is intended to help scientists and policymakers include fungi in conservation, restoration, climate agendas, and carbon models.