On not undermining the science: coherence, validation and expertise. Discussion of Invited Commentary by Keith Beven Hydrological Processes, 20, 3141–3146 (2006)

✍ Scribed by Jim Hall; Enda O'Connell; John Ewen

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 91 KB
• Volume: 21
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/hyp.6639

✦ Synopsis

Keith Beven in his recent Invited Commentary 'On undermining science?' (Beven, 2006a) called for a discussion on the topic of uncertainty in the pages of HP Today. This is a topic that we have enjoyed debating with Professor Beven in the past and we are happy to respond to his call. His Commentary argued that uncertainty analysis does not undermine science and, by the same token, we argue that subjecting uncertainty analysis to vigorous scrutiny and challenge should not undermine it. In short, we are supporters of uncertainty analysis in practically all its forms and so, by challenging the aspects of Beven's commentary, we are not seeking to undermine his aim, which we interpret as conscientious reporting of uncertainties and of the methodological assumptions used in calculating those uncertainties.

We agree that hydrologists should be challenged to apply more rigour and consistency in their reporting of uncertainties. Beven suggests that there is now only one defence against the evaluation of uncertainty in the prediction of environmental models, and that is computational cost. Yet, as he goes on to point out, even GCMs are now being run in ensemble mode and advances in parallel and grid computing are weakening even the computational defence. Uncertainty analysis of very complex models will never be easy. Since this is the case, as much effort should go into developing computational methods and reduced complexity versions (be they data-based emulators, reduced form mechanistic models or hybrids thereof), which do permit uncertainty analysis, as is invested in development of the models themselves. At the moment, uncertainty analysis is too often an afterthought for model builders. At the last count, the Hadley Centre for Climate Change Research employed 173 scientists, most of them developing and running GCMs. Fewer than 10 were involved in uncertainty analysis!