Professor Roy Thompson of the University of Edinburgh has supplied written evidence to the Scottish Affairs Committee Inquiry (at Westminster) into The Future of the Oil and Gas Industry. This evidence comes as a follow-up to his article in The Edinburgh Geologist (Autumn 2017) on ‘Can fracking, for gas and oil, power the Scottish economy?’. His key point is that, despite the North Sea being a geologically well-studied, mature oil-province, surprisingly large discrepancies remain over best estimates of oil and gas reserves. Estimates currently vary between 4.8 and 80 billion barrels of oil equivalent (bboe) for the UK continental shelf. This corresponds to a difference to Scotland’s economy of about $4 trillion – assuming approximately 90% of the oil lies in Scottish waters and commands an average price of $90 per barrel. His recommendation is that in order to determine the likely size of the UK’s ultimately recoverable oil and gas reserves, a poll of stakeholders be conducted, asking each to provide a quantitative, evidence-based estimate of economically viable production potential.