It is widely recognised that the current Irish energy system carries a significant security-of-supply risk, due to heavy reliance on natural gas, with very constrained diversity and capacity of import supply routes. This risk may become even more severe in the years immediately ahead as the only significant indigenous natural gas source (the Corrib gas field) is depleted and the other (even higher carbon intensity) fossil energy sources (coal, oil and peat) are progressively removed from the Irish energy mix. In July 2018, the Irish Academy of Engineering (IAE) published a major report assessing this evolving natural gas security-of-supply risk, entitled “Natural Gas — Essential for Ireland’s Future Energy Security” (IAE 2018). The report argued that substantial continued reliance on natural gas in the overall Irish energy system is unavoidable up to at least 2040. On this basis, it recommended a number of major strategic interventions designed to manage the consequently deepening security-of-supply risk, i.e., measures attempting to assure continued access to natural gas. In this response to that report, we present an independent peer evaluation of the basis for these recommendations. We base our analysis on the presumption that Ireland is committed to good faith action consistent with its ratification of the Paris Climate Agreement (UNFCCC 2015): specifically to play its equitable and commensurate part in holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C. We assume the IAE shares this premise. On this basis we find that the IAE analysis is mistaken both in its assessment of the required speed of decarbonisation of the Irish energy system (and therefore the need to rapidly phase out all fossil fuel emissions, including from natural gas), and in its discounting of the technical and economic feasibility of such rapid decarbonisation. On the contrary, given Ireland’s large natural resource of variable renewable energy (especially wind), and coupling this with the use of synthetic chemical fuels (“electrofuels”) for very large scale energy storage, we find that rapid fossil fuel phase out is not only technically feasible, but can progressively eliminate the security-of-supply risks associated with all imported fossil fuels, while simultaneously decarbonising with the scale and urgency demanded by good faith participation in the Paris agreement — subject, of course, to securing the comprehensive societal support necessary to enable this transformation. While the electrofuel storage element of this pathway is challenging in terms of technology maturity and immediate investment cost, this is true of all decarbonsation pathways that might credibly be commensurate with meeting the Paris climate goals; but this pathway has the unique advantages of high confidence in the effectiveness of decarbonisation and relatively rapid achievement of very high national energy security. Such a rapid fossil fuel phase out would additionally bring very significant co-benefits in balance of payments and overall national social and economic resilience. These findings also decisively contradict the IAE suggestion that continued exploration for indigenous fossil fuels is in the national interest of Ireland.