text: We ran the model using only its atmosphere and land components, with time-varying sea- 
  surface temperatures (SSTs) and sea-ice concentrations (SICs) prescribed as input quantities. This 
  approach was taken for two reasons: (i) to provide a rapid ﬁrst analysis of the implications 
  of the higher resolution for projections of climate extremes and impacts—an atmosphere- 
  only simulation requires considerably less computing time than a coupled ocean–atmosphere 
  general circulation model (GCM); (ii) to allow us to explore, to some degree, uncertainties in 
  regional climate changes by using SSTs and SICs from different climate models. To explore these 
  uncertainties in the regional impacts of climate change, we carried out six HadGEM3 atmospheric 
  simulations driven by time-varying SSTs and SICs from a subset of projections from the CMIP5 
  with the RCP8.5 scenario. The assumption here is that SSTs and SICs provide a substantial 
  inﬂuence on regional patterns of climate change over land, so using a range of SST and SIC 
  patterns in a single atmosphere model goes some way towards representing the range of regional 
  climate changes that would arise in a set of different coupled ocean–atmosphere GCMs. This 
  approach will not capture the full range of uncertainty affecting regional climate changes over 
  land, because it still relies on one atmosphere model and one land surface scheme, so responses 
  to radiative forcing that depend mainly on atmospheric process or land-atmosphere interactions 
  will still be constrained by the behaviour of that single model. Nevertheless, we consider that 
  our experimental design avoids the reliance on one single realization of climate and hence allows 
  some of the uncertainties in regional climate-change impacts to be illustrated and explored. 