Earth system dynamics are strongly influenced by land‑surface processes that operate across a wide range of temporal and spatial scales. Sub‑daily land‑atmosphere coupling shapes cloud formation and radiation transfer; seasonal vegetation dynamics modulate evapotranspiration on weekly‑to‑monthly scales and shape the hydrologic cycle; and decade‑to‑century changes in ecosystem composition and soil carbon dynamics affect the global carbon cycle and atmospheric CO₂. Human activities, such as land‑cover change, land‑management practices, and fossil‑fuel or biomass burning are the most impactful direct and indirect perturbations of the land surface. This session explores how these diverse changes, their impacts, and potential feedbacks operate from the global scale to regional hotspots. It focuses on four interlinked themes (remaining open to related topics), exploring the effects of land changes:
1. Radiative balance, including albedo changes and their effect on the planetary energy budget; modulation of land‑atmosphere coupling and low‑cloud formation; influence of biogenic volatile organic compound emissions on clouds.
2. Water cycle, including moisture recycling over land; trends in soil moisture and lower‑tropospheric humidity; CO₂-driven stomatal conductance and plant water‑stress dynamics; shifts in surface turbulent‑flux partitioning.
3. Carbon cycle, including changes in land carbon uptake and release fluxes, long‑term vegetation shifts, soil and vegetation carbon turnover, CO₂ fertilization, and nutrient dynamics.
4. Human‑societal impacts, including effects on ecosystem services such as water and food security, links between land degradation and societal vulnerability, and potential societal feedbacks.
Contributions should adopt a coupled Earth‑system perspective, investigating processes in interaction rather than isolation. We encourage submissions which (i) quantify the magnitude and direction of biogeophysical and biogeochemical feedbacks, (ii) identify key uncertainties in current CMIP‑style Earth‑system models, and (iii) propose concrete pathways to constrain these uncertainties. Innovative approaches that integrate multi‑stream observational datasets and hybrid or machine‑learning‑enhanced modeling are especially welcome. Join us in this session, hosted in partnership with the Max‑Planck‑Caltech‑Columbia‑Carnegie Center for Earth (mc‑3.org), which emphasizes this holistic view of land processes within the Earth system.