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Given even the lowest CCS scenarios considered by Bacilieri et al require a hundred-fold increase in CCS deployment to achieve the goals of the Paris Agreement, dwarfing in percentage terms the increases required in many other mitigation technologies, designing policies2 to reduce the cost of CCS with deployment must be an urgent priority. [...] Communications regarding this study focussed on the absolute difference between the two, which is large because of the scale of total energy system costs, although the report itself acknowledges that the cost-differential is only about 20%. [...] The figure below (replotted from numbers shown in figures 2b and 6b of Bacilieri et al) shows no relationship between the level of CCS deployment in 2050 and the cost of useful energy up to about 10 GtCO2 per year. [...] For example, the cluster of three very-high-CCS and relatively-low-cost scenarios represent all the cases included from one model (IMAGE 3.2), while the four IAMs in the “mid-CCS” category may well be unrepresentative (in the original database, most scenarios fall into this category, while in the subset selected for the study, they are the smallest group). [...] Hence, while there is some evidence from the IPCC scenarios that extreme reliance on CCS to allow fossil fuel usage to continue at 50% or more of the current rate in 2050 would be economically damaging, there is no evidence that the cost of useful energy is significantly impacted by the level of reliance on CCS up to 10 GtCO2 per year around the date of net zero, which is around 25% of current emi.