I have tried to show the real nature of humanity’s predicament, not because understanding its nature will enable us to escape it, but because if we do not understand it, we shall continue to act and react in ways that make it worse.
– William R. Catton Jr., from the Preface of Overshoot: The Ecological Basis of Revolutionary Change
First, I shall summarize the main ideas of Overshoot
– Humans are part of the local ecosystem, therefore to understand human society one must use the ecological paradigm, that is, look at humans the same way one would look at any other species in an ecosystem.
– All species, including humans, have a carrying capacity within the ecosystem. The carrying capacity is the largest possible stable population of that species the ecosystem can support.
– According to the ecological paradigm, humans have been able to greatly increase the carrying capacity of the ecosystem for humans by the takeover method, that is, taking biological resources which were previously exploited by different species. For example, when humans figured out how to use fire to make food more digestible, they used wood which otherwise would have gone to feed fungi. Thus, humans took a part of the biosphere which previously had been occupied by wood-consuming fungi.
– Many technological advances have increased the ecosystem’s carrying capacity for humans via the takeover method
– The takeover method is sustainable because it is about seizing a share of renewable resources from other species. Because the resources are renewable, the increase in carrying capacity is semi-permanent.
– In the year 1492, European technology allowed them to have a much higher carrying capacity per acre of arable land than the indigenous peoples of the Americas. Thus, the discovery of the Americas meant a dramatic increase of carrying capacity for Europeans, creating the ‘Age of Exuberance’. By contrast, since the indigenous human population of the Americas was already at the carrying capacity of the Americas ~with indigenous technology~, the coming of the Europeans meant that they would be crowded out of their ecological niche.
– Humans can use an increase in carrying capacity to either increase their population and/or to increase their material standards of living
– There is a limit to how much life the Earth can sustain, thus the takeover method is ultimately limited. Humans cannot use more than 100% of the biosphere, and in practice, trying to get even close to that would cause such ecological damage that it would actually decrease the ecosystem’s long-term carrying capacity for humans. In short, there is no second Earth full of resources to exploit.
– Some species use drawdown rather than takeover to TEMPORARILY increase their carrying capacity. Drawdown is when a species uses resources much faster than they can be renewed. These species drawdown the renewable resources until the resources are exhausted, which leaves the species with a population that greatly exceeds the carrying capacity. This leads to a mass die-off.
– Humans have also used drawdown during the industrial revolution – we have used nonrenewable resources such as fossil fuels, mineral deposits, etc, to enable a population boom.
– Humans have mistaken drawdown for takeover, and temporary increase in carrying capacity for a permanent increase. This is why people speak of ‘producing’ fossil fuels, when ‘extracting’ fossil fuels is a more accurate description of what is happening.
– With the use of drawdown, some humans have increased their material standards of living so much that they are now ‘homo colossus’ rather than ‘homo sapiens’ (Catton does not mean that ‘homo colossus’ is biologically a different species, it’s just a phrase he uses to distinguish high resource consumption humans from low resource consumption humans)
– Humans are already in overshoot (when a population exceeds its carrying capacity) (note: this book was published in 1980), and there is going to be a mass die-off. It is too late to prevent this.
– When a species is near or above its carrying capacity, there is great deal of intra-species competition. Humans are experiencing this with their many human-on-human conflicts.
– However, even though it is too late to stop human overshoot, there are still things humans can do to make the overshoot less bad. For example, humans can reduce their resource usage, can reduce births so the overshoot is less extreme. However, the most important thing humans can do is understand that this has been caused by ecological forces which affect all species, and is not caused by a malignant, evil Other. By understanding this as the work of fate (Catton has a nice definition of fate which does not depend on belief in theistic or supernatural entities) rather than the work of the Other, humans might be able to avoid great wars and genocides.
– People are at various stages of accepting the ecological paradigm, namely, Ostrichism (There’s nothing wrong!), Cynicism (None of this matters!), Cosmeticism (we can fix this with birth control, recycling, and environmental protection laws), Cargoism (technology will fix this!), and Realism (overshoot is here, and we must adapt as best we can). Adopting ‘Realism’ will lead to the best outcome for humans (I have to note the neat rhetorical trick of labelling people who agree with the writer as ‘Realists’ and everybody else as, er, look at the labels yourself).
This summary is long enough to be a post in itself, so I will start discussing what *I* think about all this in the next part (well, I already expressed some of my thoughts in this post).
The Notes Which Do Not Fit 