  Climate risk assessments must account for a wide range of possible futures,
so scientists often use simulations made by numerous global climate models to
explore potential changes in regional climates and their impacts. Some of the
latest-generation models have high effective climate sensitivities or EffCS. It
has been argued these so-called hot models are unrealistic and should therefore
be excluded from analyses of climate change impacts. Whether this would improve
regional impact assessments, or make them worse, is unclear. Here we show there
is no universal relationship between EffCS and projected changes in a number of
important climatic drivers of regional impacts. Analysing heavy rainfall
events, meteorological drought, and fire weather in different regions, we find
little or no significant correlation with EffCS for most regions and climatic
drivers. Even when a correlation is found, internal variability and processes
unrelated to EffCS have similar effects on projected changes in the climatic
drivers as EffCS. Model selection based solely on EffCS appears to be
unjustified and may neglect realistic impacts, leading to an underestimation of
climate risks.
