Hurricanes: Their Nature and Impacts on Society - Climate Science ...

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HURRICANES: THEIR NATURE AND IMPACT ON SOCIETY
Of course, while different decision-makers have different needs for impact
information (i.e. timeliness, accuracy, etc.), large errors in impact estimates
can have significant negative influences on specific decisions. Conversely,
certain decisions can be improved with accurate impact information. Two
scholars have asked "how do we determine whether a model has 'correctly'
simulated an impact?" (West <strong>and</strong> Lenze 1994). They find that "at present,
most evaluation in regional impact analysis is confined to the fairly simple <strong>and</strong>
non-rigorous step of asking whether the results look 'reasonable'" <strong>and</strong> they
recommend further research in the area of model evaluation.
Add in climate variability, change, <strong>and</strong> forecasts
The three risk assessment methods reviewed above will work best if the
documented past is a reliable guide to the near future. But what if the past is
not a reliable guide to the future? It has recently been appreciated that the
climatological dimensions of tropical cyclone impacts may undergo significant
variability on annual <strong>and</strong> decadal time-scales (<strong>and</strong> perhaps even longer scales
related to climate changes; Diaz <strong>and</strong> Pulwarty 1997). Further, in recent years,
scientists have begun to demonstrate some skill in interannual climate forecasts
(e.g. L<strong>and</strong>sea et al. 1994; O'Brien, Richards <strong>and</strong> Davis 1996; Glantz
1996).
Improved underst<strong>and</strong>ing of climate variability <strong>and</strong> ability to anticipate
changes in event frequency, magnitude, <strong>and</strong> location have two important
implications for efforts to better underst<strong>and</strong> tropical cyclone impacts. First,
variability on annual <strong>and</strong> decadal time-scales means that the 120 or so years
of reasonably good data on the climatology of hurricanes may not be a
reliable guide to the immediate future. Second, the presence of forecasts of
tropical cyclone activity provides risks <strong>and</strong> opportunities for decision-makers.
They present opportunities for decision-makers to alter their decision routines
in such a fashion as to incorporate new information into their plans <strong>and</strong>
policies. The forecasts also present risks because they are largely untested <strong>and</strong>
the costs of an improperly used prediction can be very large.
There are two additional methods of risk assessment that seek to utilize
information beyond that available in the historical record (Dlugolecki et al.
1996).
Event prediction
With reliable information of future events, decision-makers can implement
policies to take advantage of that knowledge. There is a large literature on
the use of climatological information by decision-makers in, for example,
agriculture <strong>and</strong> utility industries (cf. Changnon, Changnon <strong>and</strong> Changnon
1995), but very little (if any) in the area of tropical cyclones. The use of
climate forecasts of tropical cyclones by decision-makers requires research
attention.