This report assesses the potential for generating negative emissions from WtE + CCS with focus on the European waste sector as a case study. This study shows that if the entire existing European WtE fleet (i.e. 100.9 Mt of installed capacity) was retrofitted with CCS, negative emissions in the range of -50.5 to - 70.6 MtCO2/y would be generated per year, assuming a capture rate close to 100%. In its 2019 sustainability roadmap, CEWEP anticipates a total of 142Mt of residual waste generated in 2035 when meeting the thresholds for recycling (minimum of 65%) and landfilling (maximum of 10%) in accordance with the EU Circular Economy Package. It may admittedly not be possible to bridge the current ~30Mt gap in WtE capacity needed to treat the remainder of this residual waste, as some existing WtE plants come to the end of their life and others are newly commissioned. Yet, in theory, if enough WtE capacity where to be built and is retrofittable with CO2 capture, a range of -71 to -99.4 MtCO2/y of negative emissions can be achieved. When CCS limitations are considered, these ranges are naturally reduced, with a range between -20 to -30 MtCO2/y achievable when all CCS considerations are taken into account.