Critical Zone Observatories (CZOs) are instrumented field sites for monitoring hydrological fluxes, energy matter, and biogeochemical cycles - from bedrock to canopy, across terrestrial and aquatic interfaces, and across climatic and hydrobiogeochemical gradients. Networks of CZOs and their Watershed equivalents have been established and are continuing to grow and transform in many countries, including in the US, France, Germany, and Canada. Critical zones and watersheds are “human habitats”, important for sustaining basic human needs such as water, food, and energy as well as crucial for the ecosystem services they provide. The future behavior of these systems is uncertain due to changing environmental conditions as well as rapidly growing population, urbanization, industrialization and irrigation for food production. A systematic approach is needed to explore how critical zone networks are tackling the challenge of understanding and predicting their systems, including associated questions, tools and approaches. This one day workshop presents such a platform to formally bring together an international cohort of early career scientists from across these CZO/Watershed networks to initiate this systematic approach.