AbstractAn integrative hierarchical monitoring approach is proposed, with the aim of reliably detecting and assessing possible leakages from storage formations into the shallow subsurface. This hierarchical approach - with method developments and applications ranging from remote sensing (infrared spectroscopy, micrometeorology-based flux measurement), to regional measurements (geophysics and chamber based soil CO2 flux measurement), to local in-situ measurements (Direct Push Technology) - will allow large spatial areas to be consistently covered. The paper introduces a hierarchical monitoring approach applied in the MONACO project and reveals first results from measurements taken at natural analogue sites in the Czech Republic. These results indicate that the hierarchical monitoring approach represents a multidisciplinary modular concept working in different scales and resolutions.