A better understanding of greenhouse gas (GHG) fluxes from natural ecosystems is essential for improving climate prediction, mitigation, and adaptation, yet major uncertainties remain in the magnitude, drivers, and variability of these fluxes across space and time. This session highlights recent advances in observations, synthesis, mechanistic understanding, and upscaling of GHG fluxes from natural ecosystems, including wetlands, freshwater systems, forests, and grasslands. Topics include, but are not limited to:

1. measurements of CO2, CH4, and N2O fluxes across natural ecosystems and identification of their key environmental drivers;
2. synthesis of GHG flux observations across regional to global scales;
3. mechanistic understanding of spatiotemporal variability in GHG fluxes, including responses to disturbance and extreme events;
4. upscaling and modeling of GHG fluxes using machine learning, remote sensing, and bottom-up biogeochemical models.