Abstract: Dealing with uncertainty is widely recognized as the key challenge for environmental and natural resource decisionmaking. Too often, though, that challenge is considered only from an ex ante perspective which treats uncertainty as an invariant feature that must be accounted for but cannot be changed. With respect to many natural resource management decisions, that picture is misleading. Decisions are often iterative or similar, providing significant opportunities for learning. Where such opportunities are available and inaction is not feasible or desirable, learning while doing can provide the benefits of both the precautionary principle and scientific decisionmaking while minimizing the key weaknesses of each. After highlighting the benefits of a learning-while-doing approach to natural resource management, this paper briefly addresses how management agencies might be encouraged to adopt such an approach.
Uncertainty is the unifying hallmark of environmental and natural resource regulation. Dealing with uncertainty has been a major topic of academic interest for decades, but the debate has produced no firm or general conclusions.
Two alternatives frequently put forward for dealing with uncertainty are the precautionary principle and scientific principles. Typically these two are presented as standing in opposition. Precautionary decisionmaking is described as favoring regulation when there is some evidence of risk to human health or the environment. Scientific decisionmaking is described as requiring proof of harm to support regulation. In either case, the emphasis is almost always on a single forward-looking decision that must be made based on a fixed level of available information.
In this essay, I argue that a clearer picture of the challenges of uncertainty for natural resource management requires a wider temporal scope and additional degrees of freedom. Natural resource decisions typically do not present a single choice between two alternatives that, once made, remains fixed for all time. Far more often, multiple related decisions must be made over a long period of time, on the scale of years or even decades. Furthermore, the choices are more nuanced than "on" versus "off* or "open" versus "closed." There is room for a variety of conditions and limitations. Some decisions, such as how to operate a series of dams and reservoirs, what terms to include in a water pollution discharge permit, or whether and under what conditions to renew a public lands grazing lease, are explicitly temporary and therefore must be addressed repeatedly. Others are individually irreversible and therefore made only once, but belong to classes of decisions sufficiently similar that information gained from one can usefully inform another. Examples include salvage logging and wetlands filling.
One more detail should be added to this picture. Much of the discussion of precaution versus science has been framed by the specific context of regulating novel technologies or products. In that context, preserving the status quo may have economic or human health consequences, but it generally appears to protect the environment. Natural resource management is different. A legacy of past decisions made without regard for nature means that the status quo is often both bad for the environment and strongly resistant to change. The large water projects that dot the west, for example, have brought much of the region's aquatic fauna to the brink of extinction. Because they provide water to both cities and farms, however, shutting them down is not a realistic short-term option. In other situations, the need for action to correct past decisions is clear, but the effects of potential restoration efforts are not. Decades of aggressive fire suppression, for instance, have transformed open Ponderosa forests into thickets of fir. These altered forests pose a fire risk to nearby human communities, but are also inhospitable to some species native to the Ponderosa system. …