Fungi and climate. As ecosystem engineers [hyperlink glossary def] fungi are central to regulating Earth's climate because they are an integral part of the carbon cycle. Fungi play a role in climate regulation by sequestering carbon both directly, as fungal networks’ biomass is made of carbon compounds, and indirectly by helping plants to absorb and store carbon. Fungi also play a role in restoring soils and keeping them healthy. SPUN is a key player in the work to highlight the crucial role played by mycorrhizal fungi in climate management. SPUN scientists recently published research quantifying the amount of carbon plants trade to mycorrhizal fungi: approximately three quarters of Earth's terrestrial carbon, which is the equivalent to more than a third of global annual fossil fuel emissions, is drawn down from plants through fungi into soils each year.