Environmental Engineering Reference
In-Depth Information
Figure 7.12
Environmental and economic changes expected in central and eastern Canada following a doubling
of atmospheric CO
2
levels
This could lead to an increase in the incidence of
the intense low pressure systems that wrought
havoc in Britain and western Europe in 1987 and
again in 1990 (Simons 1992). Unfortunately,
current models are unable to resolve the processes
involved in these relatively small scale or regional
phenomena, and predictions on storminess in
middle latitudes remain inconclusive.
Similarly, climate models are inconsistent in
their predictions of the frequency and intensity
of tropical storms—cyclones, typhoons and
hurricanes—following global warming. These
storms only develop over oceans where sea
surface temperatures (SSTs) exceed 26-27°C.
With global warming, such temperatures would
be exceeded more frequently, and over larger
areas, than at present, leading to an increase in
the number of tropical storms. In the southern
hemisphere, with an SST warming of only 2-4°C,
tropical cyclones would become 20 per cent more
intense and form perhaps 200-400 km further
to the south than at present (Salinger and Pittock
1991). Such storms currently move out of the
tropics to become intense extratropical
depressions, which bring heavy precipitation and
strong winds to mid-latitudes. With warming
these travelling storms would be expected to
move farther north and south, sustained in part
by energy transferred from the warmer oceans.
Areas such as Australia, New Zealand and the
coasts of the north Pacific and north Atlantic
would suffer, but some of the island nations of
the south Pacific might not survive such a train
of events.
Aware of the problems they might face in the
future, the nations most likely to be affected came
together as the Alliance of Small Island States
(AOSIS), and as such were successful in having
their situation addressed as part of the UN
Framework Convention on Climate Change at
Rio in 1992. AOSIS is hoping for the creation of
a disaster insurance scheme funded by the
developed nations—whom they see as mainly
responsible for the climate change that threatens
