Geography Reference
In-Depth Information
the Caribbean, one is faced with (1) continued
predictions of increased cyclone frequency
(Emanuel 1987; IPCC 1996; Hulme and Viner
1998) with global warming and higher sea-surface
temperatures, but (2) marked changes in cyclone
frequency and spatial distribution over the past
125 years, including a recent decline in cyclone
frequency. The question therefore arises as to
which of four data sets is the most appropriate to
use in giving advice as regards future cyclone
hazards (Walsh 1998):
human systems. A few studies have been
addressing such issues, such as the work of
Bayliss-Smith (1988) and Spencer
et al
. (1997)
on the impacts of changes in cyclone
frequency and El Niño-related bleaching
episodes, respectively, on reefs and reef islands;
and of ecologists, foresters and geographers on
rain forest responses to differences and
changes in cyclone magnitude and frequency
(e.g. Whitmore 1989; Walsh 1996b) and
drought magnitude and frequency (Walsh
1996a; Condit 1998; Whitmore 1998). This
research needs to be pursued further,
preferably by interdisciplinary groups and
incorporating interactions with human
systems, if environmental responses to future
climatic change are to be predicted.
1
The entire data set since 1871.
2
The 'worst case' past record (i.e. the 1876-
1901 or 1928-58 periods).
3
The most recent period since 1959—in
which cyclones are infrequent.
4
A predicted 'global warming' scenario—with
much higher frequencies than at present.
2
Associated with this is an acute need for more
research on the longer-term changes in the
magnitude and frequency of some extreme
events, particularly cyclones and heavy
rainstorms. This is important for three reasons:
(1) to provide the long-term data series
necessary to establish temporally more robust
relationships between atmospheric circulation
variables and extreme event frequency and
spatial distribution; (2) to aid the formulation of
more soundly founded climatic models capable
of producing more reliable predictions of future
extreme event frequency than at present; and (3)
to provide the data to develop and test long-
term extreme event impact models.
The choice is not made easier given the low level
of confidence that one can place in the future
predictions of climatic models, particularly as
regards extreme events (United Kingdom Climate
Change Impacts Review Group 1996) and at
local/regional scales. In addition, there is the
problem of which rate of sea level rise to adopt
for the future, as this will greatly influence coastal
impacts of future cyclones regardless of changes in
cyclone frequency.
APPLIED GEOGRAPHICAL RESEARCH
PRIORITIES FOR THE FUTURE
3
Perhaps the greatest research need is that for
the greater involvement of human
geographers in extreme event research: (1) in
analysing historical documentary records of
extreme events and their impacts; (2) in
defining climatic extreme event parameters of
greatest relevance to human systems; (3) in
analysing and modelling impacts of changes
in extreme event frequency on contrasting
and changing societies; and (4) in designing
and assessing mitigation measures within the
context of very different cultural and societal
settings. At a time when much of research
funding is quite rightly giving greater
emphasis to 'the socio-economic dimension'
Extreme weather events remain an
acknowledged weak link in climatic-change
studies and the modelling of future climate and
its impacts (IPCC 1996; Hulme and Viner
1998). Three priorities for future geographical
research related to these research needs can be
identified.
1
Although there has been much research on
the impacts of
individual
extreme events, little
is known about their longer-term context
and the impacts that different magnitudes and
frequencies of events have on natural or
