Knowledge for better food systems

Two papers in ecological economics

These are two interesting papers on the topic of ecological economics.


Paper 1

The first - Population matters in ecological economics - argues that the issue of population growth cannot be ignored and must be addressed if progress is to be made in addressing humanity’s environmental impacts. Six main conclusions of this paper are:

  1. Using the I=f(P,A,T) formula, both population and affluence  contribute to the size of impact. Instead of playing these two factors off against each other, research is better directed at measuring their relative contributions with regard to specific impacts.
  2. If it is the case that at desirable levels of affluence (A) and realistic increases in resource efficiency (T) the present population is not sustainable, it is unwise to complacently ignore population size and/or rely on its natural peaking in several decades. Limits to food production, the precautionary principle and declining death rates all argue against complacency.
  3. Whatever the net effect on impact of lower or stable population, it substantially eases the task of alleviating poverty.
  4. There is a method withwhich individual countries can approach decisions on optimal population size (cultural carrying capacity): After determining sustainable and desirable levels of impact and the desirable level of affluence – including the welfare of future humans and other species – a realistic level of technological efficiency increase in the use of resources can be estimated. Using P=I/AT the number of people compatible with these assumptions can then be derived.
  5. When population stabilisation or reduction policies are debated, it should be remembered that they pertain to rich aswell as poor societies, and that all policies ‘coerce’ us, even ‘soft’ financial(dis-)incentives.
  6. Societies should confront the debate between procreative rights and procreative responsibilities to decide whether reproductive behaviour falls within the realm of activities legitimately controlled by democratic majority.

Ecological economics is well-equipped for many specific tasks:

  1. measuring the relative contributions to I of P, A and T analytically,using biophysical units;
  2. comparing the cost-effectiveness of the marginal impact-reduction investment, again in terms of P, A and T;
  3. rejecting high estimates of maximum human population, often based on ‘huge feedlot’ standards, whether on grounds of ecology or present utility;
  4. defining sustainable agriculture and measuring its yields per hectare, as well as sustainable fuel use;
  5. computing realistic estimates of national cultural carrying capacity so that society can formulate population-size goals;
  6. identifying and re-evaluating pro-natalist subsidies;
  7. recognising that humans compete with other species for space and resources;
  8. answering ethical questions surrounding policies for population constraint within the frameworks of inter-generational justice and the dangers of open-access commons; and
  9. applying the principle of multi-disciplinarity by explicitly discussing legal and rights issues.

Whilst any given policy to reduce population, affluence, toxicity, or inefficiency can unfortunately be compensated by expansion in other human-ecological realms, negotiating political paths to sustainabilityrequires clear decisions on desirable population goals.To close with a concrete issue, consider some questions raised by EU efforts for a biological corridor from Orkney to the Black Sea, or American efforts for one from Guatemala through the Darien Gap. Do the EU and the Americas have a moral obligation to use these entire areas agriculturally in order to feed undernourished humans? Are these corridors harder, or easier, to establish if human population grows?

Finite resources imply that population must eventually stabilise. Our only choice is to control it consciously, humanely and democratically or towait for real limits to do it for us. The intent of this paper has been to make room within ecological economics for fresh discussion of our sheer numbers.



It is an axiom of ecological economics that resource depletion and environmental pollution depend on the number of people and how many goods‐and‐services each consumes, modified by the technological efficiency of production. The paper reviews some studies quantifying the contribution of human numbers to environmental impact. It warns against playing this factor off against that of high consumption in rich countries. It asks whether from the environmental point of view complacency about either present or predicted population size is warranted. The answer depends both on fertility and mortality assumptions and on constraints such as resource and food availability. The concept of cultural carrying capacity would aid societies in determining their optimal population when account is taken not only of subsistence, but of quality of life. A population-control toolkit for both rich and poor societies is sketched, and some controversial, ‘coercive’ policy possibilities analysed.


Alcott B (2012). Population matters in ecological economics, Ecological Economics, doi:10.1016/j.ecolecon.2012.06.001

You can download the paper here (subscription access only).


Paper 2

The second paper, too, looks at the IPAT formula (Impact = Population x Affluence x Technology) but considers it in the context of the rebound effect. That is, it argues that measures by affluent populations to reduce their consumption patterns will, given a market economy and in the absence of a global cap on emissions, simply trigger greater environmental impact among poor populations due to increased consumption there.  Essentially it argues that an emphasis on encouraging individuals to change their behaviour is not an effective substitute for concerted political action – including regulations such as caps on emissions.  It concludes:

Lower consumption may have advantages on the individual, community, or regional level. There is for instance some truth in the view of Diogenes that happiness and quantity of consumption do not necessarily rise proportionally. Living lightly can offer not only less stress and more free time but also the personal boon of a better sense of integrity, fulfilling the Kantian criterion that one’s acts should be possible universally (worldwide). Locally it could mean cleaner air, less acid rain, less noise, less garbage, and more free space. And in the form of explicit, guaranteed shifts of purchasing power to poorer people it would enable others to eat better or to buy goods such as petrol and cars. However, given global markets and marginal consumers, one person’s doing without enables another to ‘do with’: In the near run the former consumption of a newly sufficient person can get fully replaced. And given the extent of poverty and the temptations of luxury and prestige consumption, this near run is likely to be longer than the time horizon required for a relevant strategy to stem climate change and the loss of vital species and natural resources. Efficiency and sufficiency strategies both offer relatively painless solutions to non-sustainability. The former is praised by ‘negawatt’ advocates not only as a free lunch, but one you are paid to eat. The latter appears to many of its addressees tolerable—switching off a few lights, riding a bike, or eating less meat, and here, too, a lunch you are paid to eat comes in the form of various health and happiness benefits.

Supply-side or other impact-side strategies, on the other hand, are hard. They confront us with the neglected question of the carrying capacity of the planet. But strictly following sustainability logic by capping extraction and/or emissions – ‘cost’ what it may – collides with our hopes and humanism. Efficiency deals with the ‘how’, the material and social technology, of our wealth-making; sufficiency speaks to us at the border between our needs and our (mere) wants, and to our inborn desire for justice. Neither addresses the taboo of population size. Both strategies distract us from the insight that nature limits us.



Alcott B (2008). The sufficiency strategy: Would rich-world frugality lower environmental impact? Ecological Economics, 64, 4 770–786

You can download this paper (also subscription access only) here.

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