Environmental Engineering Reference
In-Depth Information
to predict the relationship between carbon dioxide emissions and global temperature
generate differing predictions, leading to ambiguity. Uncertainty, ignorance, and am-
biguity all make for difficult decision making.
People, including planners, obviously prefer to make decisions in situations with
known probabilities rather than in situations of uncertainty. However, when con-
fronted with uncertain situations, like those that will likely occur due to climate
change, people often behave in one of two ways. First, they try to avoid making deci-
sions under such conditions, and they tend not to make decisions consistent with the
principles of rational behavior (Fox and Tversky 1995). Second, they will make deci-
sions as if they have probabilistic estimates of the outcomes (i.e., as if it were a risk cal-
culation). Moreover, they typically develop these probabilistic expectations them-
selves and may not use information, even scientific information, correctly to do so
(Ellsberg 1961). These are behaviors that must be recognized and overcome in order
to meet the challenges we will face as climate change modifies our social and ecolog-
ical environment.
Investment in financial capital provides lessons we can use for planning invest-
ments in natural capital through restoration and conservation. For instance, with per-
fect knowledge of the future, an investor would focus solely on the investment with
the greatest return. However, when confronted by an uncertain future an investor
may diversify her investments in order to reduce the overall level of uncertainty
(Markowitz 1991). A similar approach would be appropriate for restoration planning.
Just as an investor would like to focus on one risk-free option, restoration planning
would be less expensive with one certain future scenario. Without this certainty, res-
toration planners must be prepared for some investments to fail and target investments
across a range of most likely future scenarios. This approach is already in effect in
water-scarce areas, such as Australia and California, for maintenance of water quantity
and quality (Lempert and Groves 2010; Marinoni et al. 2011). As consensus develops
among predictive models about the effects of climate change on ecosystems, appro-
priate portfolio elements will become more apparent, such as habitat for species most
susceptible to identified climate-driven changes (Pereira et al. 2010).
Successful restoration planning requires identification of known risks to project im-
plementation and long-term viability, and testing to explore the likely outcomes of new
strategies that will be needed to address these unprecedented conditions. Climate
change also introduces challenges in terms of planning and weighing risks and out-
comes across expanding time frames. While it might have been sufficient to consider
time frames ten or twenty years into the future, restoration planners must now consider
demands on, and anticipate conditions for, projects out fifty or more years. In addition,
they must recognize the potential for different and unprecedented environments due
to tipping points and irreversible thresholds triggered by climate change (Lenton et al.
2008). Since people have more difficulty evaluating distant risks, particularly if they
might be borne by future generations, coordinating local and current cooperation for
truly long-term restoration projects will require more explanation and education.
Communicating the complexity associated with the risk, uncertainty, and ig-
norance associated with climate change and natural systems can present additional
