Limits of Acceptable Change and Judgments about Impacts

I recently completed a draft manuscript of a handbook on tourism and the environment. I was asked to write a chapter on Limits of Acceptable Change and Tourism. In writing that chapter, I decided it was important that readers not only have the opportunity to read about the steps to the LAC framework, but also be exposed to certain issues which have arisen in the literature including carrying capacity. Now I cannot reveal all that I wrote, but I thought I would raise the question of a couple of strengths of LAC in relation to some of the criticism I sometimes see.


Now if you don’t know what LAC is, it is a process designed in the mid-1980s to help Wilderness managers in the U.S. grapple with the question of managing visitors and their impacts, both social and biophysical. Since then, it has become widely known and practiced both in the U.S. and abroad. Several variants exist, including the US National Park Service designed Visitor Experience and Resource Protection (VERP) process, but LAC remains a very visible process.

One of the criticisms that LAC and similar frameworks receive is that they allow degradation of biophysical conditions to occur, that by allowing some change to occur, impacts are deemed socially acceptable, thus leading to a gradual, inevitable loss of the qualities for which the area was designated. The criticism goes on to often include a statement along the lines that if managers would establish a carrying capacity, such degradation would not occur. Of course, I believe that this criticism is based on a mis-understanding of the relationships between use levels and impact and a miscasting of the standard setting process that is a part of LAC.

First, in a nature-dominated setting, such as a designated Wilderness, national park backcountry or similar area, any level of human use leads to some changes in the natural environment. When a hiker, for example, walks along a previously unused area, there is an impact—however slight, even if not measurable with current technology. Impacts occur relatively quickly, disproportionate to use levels. This conclusion has been well established in the recreation ecology literature for decades. So, if visitors are allowed to use an area, then some impact will occur. The question then becomes not one of preventing impacts but one of determining how much impact would be acceptable given the natural heritage present, demand for the area and objectives established for it. Whether an impact is one that can be described as “degradation” is another decision. The LAC process makes the determination of acceptable change explicit, subject to debate and part of the social discourse around protected area management.

Second, the practical implication of carrying capacity, as it has been applied in the literature, shows that visitor use is often permitted, thus impacts occur, and as a result, degradation of natural heritage might happen. However, in establishing such carrying capacities, the judgments about the acceptability of such impacts are often hidden, not subject to review, debate and discourse. Those judgments reflect not a healthy public engagement process but rather an elite that has been privileged to make such decisions. The unfortunate thing about this is that the people making such decisions may not even understand that they are making decisions about acceptability of impacts. These decisions may be hidden in an illusion of scientific objectivity, they may buried in assumptions, often only implicit, that are never revealed because the research is never subject to debate because of the overall elitist stature of science.

Now, I am not opposed to science. We absolutely need science and the knowledge it generates to help us move forward and strengthen our protected area management capabilities. But, science helps inform decisions, not direct them. The process of protected area management is filled with value judgments, such as the ones involved in setting standards. What we want to do is to explicate that process so it is transparent and so that decision makers can be held accountable. LAC does this, carrying capacity does not.