Environmental Engineering Reference
In-Depth Information
Figure 7.9
Change in global soil moisture levels following a doubling of CO
2
. (a) December, January and
February, (b) June, July and August
Source:
Compiled from data in Houghton
et al.
(1990)
years ago, also suggests that the greatest impact
of any change will be felt in mid to high latitudes
in the northern hemisphere.
The models used to investigate global change
are usually considered to provide less accurate
results at the regional level, but they do support
these past geographical trends. Following a
doubling of CO
2
, the Canadian Climate Centre
GCM indicates a warming of almost 5°C for the
southern part of the country, summer and winter.
In the north, the seasonal differences would be
considerable, with a mean temperature increase
of 8-12°C in winter, but less than 1°C in summer
(Hengeveld 1991). Similar values are predicted
