Today’s post is that which was intended for last Monday. However, thanks to the happy coincidence of incoming information, Monday’s post was taken up with summarising an 11-year old presentation by Dr Albert A. Bartlett, entitled ‘Arithmetic, Population and Energy’, which is the best summary I have yet seen of the insidious problems caused by exponential growth. Even if you think you understand the maths – and are familiar with concepts such as doubling time and illustrations such as 264 grains of rice on a chessboard – it is still worth watching the a series of eight 9-minute videos, or entire presentation, posted on YouTube. This is primarily because of all the evidence Bartlett presents, which suggests that anyone who says exponential growth and/or resource depletion is not a problem is either stupid or a liar. It really is that simple. However, I should also wish to draw attention to two further happy coincidences – two recent posts by fellow bloggers that are well worth reading: 1. “The greatest shortcoming of the human race is our inability to understand the exponential function.” – another post about Bartlett’s presentation by Jules Bywater-Lees. 2. The Great Unmentionable by George Monbiot – a self-explanatory post by Paul Handover. Today, then, I will finally get round to summarising the recently-published paper by economist Partha S. Dasgupta and biologist Paul R. Ehrlich, entitled ‘Pervasive Externalities at the Population, Consumption, and Environment Nexus’. As I said on Monday, the abstract is viewable on the Science journal website, but, having done a quick Google search, I found the entire paper published as a PDF by Dasgupta on the website of Cambridge University. Here, then, is my summary of the paper:
‘Pervasive Externalities at the Population, Consumption, and Environment Nexus’, by Partha S. Dasgupta and Paul R. Ehrlich.
Introduction (in lieu of Abstract) The authors start by pointing out that externalities (i.e. unintended consequences) in economics are widely acknowledged but generally relate to human use of the natural environment. Thus, people talk about our collective failure to value the essential ecosystem services Nature provides. In strict contrast to this, the authors suggest that the adverse consequences of resource consumption and population growth are generally not acknowledged. Reproductive Externalities The authors then begin by suggesting that birth rates in Europe began to decline 400 years ago as a result of improvements in the standard of living of most people because, almost counter intuitively, it led to people delaying marriage and childbirth until they could afford to set up their own household. However, birth rates in developed countries have since fallen much further and faster with improvements to the education and emancipation of women; and the advent and acceptance of contraception. The authors note that, today, population growth is greatest in poor countries. However, unlike Bartlett, they do not acknowledge that per-capita rates of consumption make modest population growth in wealthy countries even more problematic. Instead, the authors focus on the factors that continue to encourage high birth rates in poor countries (in sub-Saharan Africa in particular). Under the title ‘pro-natalist institutions’, the authors discuss societal norms such as the fostering of children by non-biological parents; communal land tenure (as opposed to the division of land amongst children that could discourage large families). Although seemingly careful not to mention the effect of religious beliefs, the largely “unmet need” for family planning is acknowledged. The authors also seem to be optimistic that lowering birth rates can be achieved faster through increasing access to contraception than it may be by improving education. Irrespective of how it is achieved, the authors acknowledge that achieving it will be essential to halting global human population growth. Notwithstanding, for the moment, that the ecological carrying capacity of the planet may have already been exceeded, the authors point out that whether or not global human population growth stabilises depends mainly on average family size in the future. Under the title ‘conformity’, the authors discuss the reality that people continue to have large families long after the original reason for doing so (e.g. high infant mortality and lack of good healthcare or social welfare) has diminished or disappeared. On a more positive note, the authors suggest that the desire to conform can be broken if a big enough minority can be encouraged to modify their behaviour (i.e. and defy convention). Under the title ‘breakdown of the commons and the added need for labour’, the authors discuss the externalities arising from the predominance of subsistence economies. These are the things that keep poor people poor, such as the labour intensive nature of many agricultural practices in the absence of mechanisation; and the fact that children who are fetching water, gathering fuel, working the land, or looking after animals are often missing out on being educated as a result. Consumption Externalities The authors start by stating the obvious: the consumption (and depletion) of resources has consequences for both current and future generations. In terms of consequences for people alive today, the most obvious adverse consequence of resource consumption – or rather pollution by the waste being generated – is highlighted as being ongoing global climate disruption. The authors then focus on what drives us to consume things and to do ‘competitively’ and ‘conspicuously’ (i.e. to equate consumption with progress, fulfilment, and happiness). Here too, the authors highlight the troubling reality of social conformity as a driver of persistently self-destructive behaviour. Environmental Externalities Once again, the authors acknowledge previous discussion (in academic literature) of anthropogenic impacts upon the environment and choose to focus on those that are detrimental. They suggest that these can be categorised as either unidirectional or reciprocal: the former being impacts the authors describe as “externalities each party inflicts… on all others, as in the case of unmanaged common property resources”. The authors then highlight that, unlike commonly owned resources at a local level, global resources that are not owned by anybody (such as the atmosphere and the fish in the sea) tend to be become polluted or over-exploited. Difficulties in Enacting Policies to Counter Externalities The authors begin their discussion of all of the above by lamenting the popular misconception by economists of Nature as something that is “a fixed, indestructible factor of production”. This rather opaque statement incorporates a variety of fallacies, including that Nature has only instrumental value; that it has an infinite capacity to provide resources for our use; and that it has an infinite capacity to assimilate (or recycle) the wastes we generate. These are all serious misperceptions of reality: Nature’s resources are finite and its essential ecosystem services are non-substitutable. For example, if human activity continues to decimate bee populations, at what point will it start to impact upon our ability to grow fruit and cereal crops? Indeed, is this not already happening? As in many other discussions of the environment, the authors highlight the non-linearity of many processes in Nature; and the existence of positive (i.e. self-reinforcing or mutually-destructive) feedback mechanisms. Thus, they construct the population consumption environment nexus as three corners of a triangle with each having an effect upon – and being affected by – the others. Towards the end of their discussion, the authors highlight the fact that 15 of the 24 major ecosystem services examined in the Millennium Ecosystem Assessment were found to be either degraded or currently subjected to unsustainable use. Even more worryingly, they cite the conclusions of numerous other studies that, if all 7 billion of the people on the planet today were to squander resources at the rate at which those who are already wealthy do, “at least two more Earths would be needed to support everyone on a sustained basis”. Considering the consensus view of UN statisticians that, on its current trajectory, the world population could exceed 10 billion by 2050, the authors make the obvious point that, if realised, “the demands made on the Earth system will prove to be even more unsustainable”. So it is, then, that the authors end their discussion of the issues by considering the prospects for technology alone to solve this problem. They start by noting that technology does not operate in a vacuum (i.e. it too consumes resources) and that innovators respond to incentives (so government policies are important). Reflecting recent pronouncements by the IMF, the authors highlight the fact that Nature’s essential ecosystem services are currently grossly under-valued (e.g. the price of fossil fuels does not currently reflect the damage our use of them does to our environment). The authors also cite historical and empirical evidence that suggests that innovation and technology has historically increased unemployment; and archaeological evidence that past civilisations collapsed as a result of degradation of their environment or an inability to respond fast enough to environmental change. This should be of great concern to all humans alive today, because the current rates of environmental change are almost certainly unprecedented in the period of time over which such civilisations have existed. Conclusion I will let the authors’ conclusion speak for itself:
Although their magnitudes are likely to differ across societies, owing to differences in societal histories, institutions, customs, and ecologies, the reproductive and consumption externalities we have identified here share striking commonalities. Moreover, the analysis has uncovered reasons why technological innovations since the Industrial Revolution have been rapacious in their reliance on natural capital. We have shown that the externalities studied in this paper are not self-correcting. Therefore, the analysis we have presented points to a spiralling socio-environmental process, giving credence to the presumption that the pattern of contemporary economic growth is unsustainable.