Changes in climateextremes 131(^53)
7
5
2
2
2
Greenhouse/control
5
5
5
5 5
3
12357
1
2
1
(^222)
7
Figure 6.8The changing probability of extreme season precipitation in Europe
in winter as estimated from an ensemble of nineteen runs with a climate model
starting from slightly different initial conditions. The figure shows the ratio of
probabilities of extreme precipitation events in the years sixty-one to eighty of
eighty-year runs that assumed an increase of carbon dioxide concentration of
one per cent per year (hence doubling in about seventy years) compared with
control runs with no change in carbon dioxide.
prolonged periods of no rainfall at all (see Figure 6.9). In other words,
much more likelihood of drought. Further, the higher temperatures will
lead to increased evaporation reducing the amount of moisture available
at the surface – thus adding to the drought conditions. The proportional
increase in the likelihood of drought is much greater than the proportional
decrease in average rainfall.
Thus in the warmer world of increased greenhouse gases, different
places will experience more frequent droughts and floods – we noted in
Chapter 1 that these are the climate extremes which cause the greatest
problems and we will be considering the impacts in more detail in the
next chapter.
What about other climate extremes, intense storms, for instance?
How about hurricanes and typhoons, the violent rotating cyclones that
are found over the tropical oceans and which cause such devastation
when they hit land? The energy for such storms largely comes from
the latent heat of the water which has been evaporated from the warm