chapter - Atmospheric and Oceanic Science

Climate scenarios
this would be related to a combination of changes in the gradients of the surface
temperature and of those of the middle troposphere (Räisänen 1997; Fyfe et al.
1999; Kushner et al. 2001). Likewise, over extensive regions of high latitudes of
both hemispheres, the signal of mean change overcomes the one of the standard
deviation indicating a consistency in the response to the different models.
Table 12.3 shows evaluations about the degree of reliability on the changes
observed in the last half of XX century and those projected for XXI in extreme climatic
events (IPCC 2003). This evaluation resulted from the analysis of observations
and results provided by GCMs. Some extreme phenomena at spatial and/or
small temporal scale such as storms, tornadoes, hail events and electric discharges
are not included since they are not represented by the GCMs.
Table 12.3. Evaluations about the degree of confidence in the observed and projected changes in climate
extremes (IPCC 2003).
Degree of confidence in the Degree of confidence in
observed changes Climate changes the projected changes
(second half of XX century) (during XXI century)
Higher maximum temperatures
Likely and more heat in almost Very likely
all land regions
Very likely
Higher minimum
temperatures, less cold
and frosty days in almost
all the land regions
164
Very likely
Lower amplitude in daily
Very likely temperature in most Very likely
of the land regions
Likely in many regions
Likely in many middle and
high land regions of
the northern hemisphere
Rise in the index of heat Very likely in most
in land regions of the regions
More episodes of Very likely in
intense precipitation many regions
Higher Summer continental
Likely in some regions dryness and drought
related risk
Not observed in the scarce
available analyses
Increase of maximum and
Insufficient data to make mean intensities of
an evaluation precipitations of
tropical cyclones
Likely in most of the
interior continental
regions of
middle latitudes
Increase of maximum
intensities of tropical Likely in some areas
cyclones winds
Likely in some areas