 We found that the differences in projected changes of mean annual runoff between the two types of hydrological model can be substantial for a given global circulation model, GCM, an absolute GHM-CHM difference in mean annual runoff percentage change for UKMO had CM32 degrees Celsius warming of up to 25%. However, these differences were relatively small compared of projections across the seven GCMs. Therefore, for the six catchments and seven GCMs we considered, climate model structural uncertainty was greater than the uncertainty associated with the type of hydrological model applied. Additionally, shifts in the seasonal cycle of runoff with climate change were represented similarly by both hydrological models, although for some catchments the monthly timing of high and low flows differed. This implies that for studies that seek to quantify and assess the role of climate model uncertainty on catchment scale runoff, it may be equally as feasible to apply a GHM, MAC PDM 0.09 here, as it is to apply a CHM, especially when climate modeling uncertainty across the range of available GCMs is as large as it currently is. This article was authored by S. N. Gosling, R. G. Taylor, N. W. Arnell and others. We are article.tv, links in the description below.