2.7.3. Relevance and Use of DAFs in Sectoral Adaptation DecisionsSelected
Working Group II has reviewed a huge volume of climate impact assessment studies
conducted to date. Most of these studies investigate possible implications of
climate change for a single economic sector or environmental component. An increasing,
yet still small, fraction of these studies lists options to alleviate impacts,
but few take even the next step of exploring direct and indirect costs of those
adaptation options. Even fewer studies provide comprehensive assessments of
direct and indirect benefits.
Although these studies qualitatively indicate that many policy options proposed
as adaptation measures to reduce negative impacts of climate change would be
justified even in the absence of climate change (dubbed "no regret"
measures on the impacts adaptation side), to date very few have been developed
to the point at which comprehensive and quantitative assessment of adaptation
options would be possible. Nevertheless, they are a prerequisite for establishing
appropriate applications of the more quantitative DAFs reviewed in Section
2.7.2. The main reason is that, despite uncertainties of regional climate
change patterns and resulting impacts, some information is generated about possible
biophysical impacts. However, little is known about future socioeconomic sensitivity
and even less about future adaptive capacity. Resolving this would require fairly
detailed regional development scenarios to provide the broader context for sectoral
assessments. All these factors together make rigorous applications of quantitative
A simple ranking of climate impact and adaptation studies according to how
far they get in using DA tools would start with those that are preoccupied almost
exclusively with impacts and casually mention some obvious adaptation options.
The next category would be studies that attempt to produce a comprehensive list
of possible adaptive measures. More advanced studies would explore positive
and, if they exist, negative effects of listed options and try to establish
at least a qualitative ranking. By assigning monetary values to those comprehensive
effects, CBA could help determine the optimal level of adaptation measures;
CEA would select the least-cost solution to provide a predetermined level of
Perhaps the most crucial area of public policy in climate change adaptation
is water resource management. A set of papers arranged by Frederick et al.
(1997a) looks at different aspects of climate change and water resources planning.
Their general conclusion is that DAFs adopted in public policy procedures of
water management are largely "appropriate for planning and project evaluation
under the prospect of climate change, but new applications and extensions of
some criteria may be warranted" (Frederick et al., 1997b). The authors
mention nonstationarity, interest rates, and multiple objectives as issues on
which progress is required to support better assessments of climate change adaptation
Water is an important factor to consider in most other sectoral impact and
adaptation assessments, even if their primary focus is on a single sector. With
a view to the complexity of interactions among sectoral impacts on one hand
and adaptation measures on the other, integrated regional assessments increasingly
are considered to be indispensable to understand climate-related risks.