because of social, political, economic, and technological
changes in or affecting coping systems and changes in individuals'
abilities to use these systems. The adequacy of estimates of the
consequences of future climatic events therefore depends on
realistic assessments of these changes in social systems. For
example, the expansion of global markets into new regions decreases
vulnerability to local droughts for people in those regions who
have sufficient resources to buy food in those markets; it may,
however, have an opposite effect for low-income people in the same
region if it undermines preexisting social norms for sharing with
the poor. A new flood-control dam reduces vulnerability to seasonal
floods below the dam, and an educational program may get more
people to purchase flood insurance.
The effectiveness of coping systems may also change over time.
The aftermath of Hurricane Andrew illustrates the phenomenon. In
the decades before the hurricane, during which there were few major
hurricanes in Florida, major population increases were occurring
there, and little attention was being paid to reducing
vulnerability through stormresistant building construction
techniques. As a result, the disaster insurance industry was not
fully prepared, and there were serious disruptions in the cost and
availability of coverage for some time afterward. In addition, the
building stock in the region was much less hurricane resistant than
it might have been.
These changes affect climate sensitivity and the potential value
of forecasts. Therefore, efforts to anticipate the effects of
climatic events or provide useful forecast information should take
into account the possibility that, by the time a climatic event
occurs, the target sectors may be in a considerably different
situation in terms of vulnerability and of the coping possibilities
available than when estimates of climate sensitivity were made.
Successful coping with climatic variations sometimes depends
on nonclimatic information. For example, farmers consider crop
prices and price forecasts when making planting decisions to hedge
against climatic events. Fishers consider information on fish
stocks as well as climate forecasts in deciding how intensively to
fish. Households and firms consider the price and coverage offered
by disaster insurance providers. Such considerations may be obvious
to the decision makers, but they may need to be brought to the
attention of climate analysts.