Carrying Capacity

Carrying capacity
I just read an article about the concept of carrying capacity. On it, the author exposes the conception of this concept and its appliances to a diversity of examples in biology and demography, as well as on human ecology. The conception of this idea is traced back to Malthus essay on human population growth. Then it shows the extended influence of this essay in many thinkers of the time (17th century) and since then; and specially, in Darwin’s work and therefore in biology and some of the must accepted scientific theories today. Nonetheless, it also shows the flaws that lay behind this concept and the problems it suppose when applying it to complex biological and social systems. It continues explaining some of the applications that some scientists have proposed on this concept and the limitations it has in different examples. It concludes that the concept is not useful when applying it to complex systems but for a very small time and a limited sample of variables. When trying to set “carrying capacities” to population growth, resource consumption or ecosystems resilience, there would be a number of “upper limits” to consider, and since there could be not an objective value for such limits, it would require institutional consensus or value judgments to set such limits.
Now, this is a very important discussion. When thinking about sustainability, growth, population, and parameters such as life quality, it is impossible to leave out this concept “carrying capacity” or at least, “upper limits” to some parameters. One important example is the upper limit of atmospheric CO2, set at 400 ppm by the IPCC, and the 2 degrees planetary temperature increase. These limits where set based on a series of scientific observations and suppositions that were agreed by an institution composed by a very large number of scientists from many countries around the world.
This is an example of how a consensus could be made to agree on upper limits for specific parameters. Now, there are many issues that cannot be so easily settled. For example, population growth. How could a panel of experts set an upper limit for population growth. Based on which parameters. Would it limit the growth of some ethnicities and others not, would it prioritise diversity, social status, certain capacities over others. The problems that rise from this issue are countless. I believe it is not possible to undertake such a task under the same conditions as the IPCC has made for CO2 concentrations.
I would like to explore the idea of a more local approach. What if the settling of upper limits for population growth would be left to localities or regions, based on the local knowledge on recourse availability and consumption patterns, for example, instead of a top down policy that would impose upper limits based on parameters that could be nonsense in many cases.