Science4CleanEnergy, S4CE, is a multi-disciplinary consortium, of world-leading academics, research laboratories, SMEs and industries. S4CE will develop a project that includes fundamental studies of fluid transport and reactivity, development of new instruments and methods for the detection and quantification of emissions, micro-seismic events etc., lab and field testing of such new technologies, and the deployment of the successful detection and quantification technologies in sub-surface sites for continuous monitoring of the risks identified by the European Commission. S4CE leverages approximately 500M EUR in existing investments on 4 scientific field sites. S4CE will utilize monitoring data acquired during the project in these field sites on which (a) it will be possible to quantify the environmental impact of sub-surface geo-energy applications; (b) new technologies will be demonstrated; (c) data will be collected during the duration of the project, and potentially after the end of the project. Using reliable data, innovative analytical models and software, S4CE will quantify the likelihood of environmental risks ranging from fugitive emissions, water contamination, induced micro-seismicity, and local impacts. Such quantifications will have enormous positive societal consequences, because environmental risks will be prevented and mitigated. S4CE set up a probabilistic methodology to assess and mitigate both the short and the long term environmental risks connected to the exploration and exploitation of sub-surface geo-energy. S4CE will maintain a transparent dialogue with all stakeholders, including the public at large, the next generation of scientists, academics and industrial operators, including training of young post-graduate students and post-doctoral researchers. S4CE will deliver the independent assessment of the environmental footprint related to geo-energy sub-surface operations, having as primary impact the assistance to to policy making.