Feb 1, 2016

Human influence on climate in the 2014 southern England winter floods and their impacts

by
Nathalie Schaller, Alison L. Kay, Rob Lamb, Neil R. Massey, Geert Jan van Oldenborgh, Friederike E. L. Otto, Sarah N. Sparrow, Robert Vautard, Pascal Yiou, Ian Ashpole, Andy Bowery, Susan M. Crooks, Karsten Haustein, Chris Huntingford et al
,
Nature Climate Change
  • States that a succession of storms reaching southern England in the winter of 2013/2014 caused severe floods and £451 million insured losses
  • Finds that anthropogenic warming (in addition to increasing the amount of moisture the atmosphere can hold) caused a small but significant increase in the number of January days with westerly flow, both of which increased extreme precipitation.
  • Hydrological modelling indicates this increased extreme 30-day-average Thames river flows, and slightly increased daily peak flows, is consistent with the understanding of the catchment’s sensitivity to longer-duration precipitation and changes in the role of snowmelt
  • Consequently, flood risk mapping shows a small increase in properties in the Thames catchment potentially at risk of riverine flooding, with a substantial range of uncertainty, demonstrating the importance of explicit modelling of impacts and relatively subtle changes in weather-related risks when quantifying present-day effects of human influence on climate