The EU has big and growing ambitions for emissions reductions by 2030: down 40% below 1990 levels, increasing the share of renewables to 32% of final energy consumption and improving energy efficiency by 32.5% above business-as-usual. These targets will be further revised as the more ambitious goal of cutting emissions by 55% by 2030 becomes legally binding. This means the EU as well as individual nations must estimate the cost of meeting these goals. Carlo Stagnaro and Carlos Di Bonifacio at Istituto Bruno Leoni have reviewed the individual National Energy and Climate Plans (NECPs) and warn there is a wide variation of methodologies and cost/benefit results. In other words, they give the EU no useful guide to how much it actually needs to spend. As an example of the range, the EU-average expected total investment cost to cut one ton of CO2 is €522/annum. The highest-cost countries are Portugal (€1,645), Italy (€1,312), and Bulgaria (€1,174). The least-cost are Estonia (€47), Lithuania (€67), and Denmark (€82). The authors strongly urge the EU Commission to help the member states revise their NECPs and make them consistent and transparent. The climate challenge is too important, and the amount of money to be mobilised too large, to get away with loose numbers.