We have viewed the report by N-56 (22 August) on the potential for unconventional oil and gas extraction from the Kimmeridge Clay in the North Sea using fracking and we agree this has significant potential. Using the technology there is potential to double the reserve base of the North Sea, bringing in an additional £300bn from Scottish waters. While there are still economic and technological challenges to overcome, it is also true that 10 years ago no one predicted the shale gas revolution that has transformed the economic fortunes of North America. Offshore fracking also has the advantage of being far less invasive and challenging to society. Once again we see how the ingenuity of the oil exploration community continues to add huge potential resources to proven reserves. We can look forward to a long future of oil and gas wealth from the North Sea.
Professor John Howell Chair in geology & petroleum geology, University of Aberdeen; Alex Russell Professor of petroleum accounting Peter Strachan Professor of energy policy, Aberdeen Business School at Robert Gordon University
• George Monbiot’s scathing depiction of the English oligarchy does not support his inference that Scotland would be better out of the UK (Comment, 3 September). The interest rate decisions of the monetary policy committee are not the only influences on the currency which the SNP plans to share with the rump UK. The Treasury, the banks and City institutions all play a part. Achieving political independence is not the same as gaining economic independence.
A separate Scotland would lose the manifold political and business influences its representatives can exert on the shared currency. Many Greeks, Portuguese and other Europeans would no doubt refer the Scots to Keynes’s aphorism: “He who controls the currency controls the country.” Relieved of moderating pressures from within the UK framework, the oligarchs would probably have more control over Scotland’s economy than they do at present.