However, in most cases, the effects of global warming on air and water temperatures are
likely to be far more complicated that a gradual increase in average temperatures. In
many regions, daily minimum air temperatures have increased more than daily maximum
temperatures, leading to a reduction in the diurnal temperature range (Easterling et
al., 1997). Both observational studies and models of future climate change suggest that
there will be more hot summer days and fewer cold waves (Easterling et al., 2000). Regionally,
temperatures are likely to become more variable, and this increased variability
(i.e. a 1°C increase in the standard deviation of temperature) will lead to a far greater
frequency of extreme temperature events than a similar change in the mean temperature
would (Meehl et al., 2000).