Carrying capacity
Absenting predation, disease and intra-species aggression, populations of mammalian wildlife and humans are ultimately constrained by the ecosystem services available to them. Thomas Malthus was making this point two and a half centuries ago. He suggested that humankind had a propensity to use abundance for population growth rather than for improving living standards. During the last half century, populations in some developed countries have, in response to better education, easier birth control methods and an increased desire for material possessions, bucked Malthus’ generalisation, creating the so-called demographic transition, characterised by ageing populations.
However, this situation is still far off in Africa and, in those parts of the world where it is occurring, seems to cause a great deal of worry to elected politicians. It is hard to see how material living standards can increase with shrinking work forces and expanding numbers of old people. Can a democratic system of government survive in a state in which citizens become progressively poorer?
All elected politicians strive for increasing economic growth in order to be able to promise their citizens more “bread and circuses”. To this extent, they give the impression that utopia can be achieved. Nevertheless, it seems fairly obvious that, if civilisation is to survive, we can’t, in the long term, continue to expand our numbers in order to dodge the perceived adverse economic consequences of demographic transition.
Sooner or later, we’ll have to pass through it, preferably sooner because later could be too late. Perhaps, Thomas Hobbes, father of political philosophy, was, after all, correct in his book “Leviathan”, published in 1651. He essentially argued that, unless citizens agree to give up their individual rights to a supreme ruler and agree to obey society’s laws, whether they agree with them all or not, there will be no “common wealth” and no civilisation.
The consequence will be miserable, brutish subsistence with continuous conflict. Shortly after Hobbes, John Locke espoused a more liberal philosophy and his thinking was later influential in the writing of the American Constitution. Unlike Hobbes, he thought that human nature was characterised by reason and tolerance (provided divinely) and that governments need the consent of the governed, adding that the governed had rights to revolt against authority. We may be reaching the point of discovering whether Hobbes or Locke was the better political philosopher!
Despite the fact that some human populations have apparently managed to avoid the worst consequences of the predictions of Malthus, it is undeniable that wild animal populations cannot. All other things being equal, the latter will generally keep breeding until their food supplies run out and then they’ll go hungry, lose condition and even starve.
Unfortunately for them, they are in direct competition with man who has, in large part, co-opted those habitats that offer superior ecosystem services (in the form of fertile soils, better rainfall and accessible water supplies) and forced them into less productive areas.
Under such circumstances, is it unreasonable of conservation managers to attempt to make the best of a bad job by, for example, providing sources of accessible water or erecting fences to avoid human/wildlife conflict? It must be acknowledged that the provision of artificial sources of water to a confined animal population will inevitably lead to overgrazing and thence habitat damage.
It is utopian to suppose that species of wildlife can undergo demographic transition without, first, causing habitat deterioration. It is presumably because they recognise this as fact that wildlife researchers who cannot countenance control of numbers by culling suggest that habitat can only be protected by closing waterholes, removing fences and providing more space.
Regrettably, this is rarely practical or affordable – although trans-frontier conservation areas offer some hope. I take the Hobbesian view that wildlife managers should undertake the roles of supreme rulers of the areas for which they are responsible. They should rule in the general interests of the ruled rather than being overly concerned over individual animals or particular species thereof. The maintenance of habitat sustainability should be their main guiding criterion.
In a presentation, entitled “Our Environmental Dilemma”, Peter Ardington explained that man and his domesticated stock already comprise some 90% of the total of all mammalian biomass (as far as species of 20kg or more are concerned). Furthermore, he cited a WWF document that claimed that global ecosystem services could sustainably support only 3 billion humans living at developed world standards. The fact that the human population has reached 7 billion and will inevitably continue to increase doesn’t necessarily imply that this is environmentally sustainable – we could be in overshoot mode, made possible only by mining energy from fossil fuels at rates thousands of times more quickly than it took to create them.
This is leading to undesirable climate change, but, in Ardington’s view, loss of topsoil through inappropriate ploughing and over-grazing represents a more acute problem. In my opinion, Ardington’s points are well made, but they can be challenged. One must consider the “size of the cake” question.
When economists argue the case for continued growth, they tend to suggest that, even when such growth may have to be achieved by avoiding the consequences of demographic transition by, for example, immigration, each member of the expanded population can still hope for a larger slice of the cake because it will become bigger in its entirety.
Ecologists are apt to question the validity of this contention. Garrett Hardin, better known for his “Tragedy of the Commons” assertion (to which I’ll return), argued that natural scientists accepted that there were limits to growth while social scientists (such as economists) tended not to. He used the analogy of a lifeboat to demonstrate the problem being faced by our planet.
The lifeboat can hold 60 people and currently contains 50. There are still 200 in the water who will drown if they can’t get aboard. If they all try to board, everyone will drown. Clearly, this gives rise to endless ethical dilemmas and there is no generally agreed approach to the best resolution. These dilemmas are, in fact, currently arising in the real world. Those who believe in both individual rights and social justice tend also to support a welfare state.
Can this go on into the future? Suppose I choose to produce 6 children but can only provide support for one? The state (i.e. the other citizens within it) will be expected to pick up the tab for rearing the other 5. Furthermore, all 6 will be expected to be provided with equality of opportunity with those offspring of more forbearing parents. Social justice it may be, but for whom? Peoples’ attitudes to such matters are shaped more by emotion than logic and the human characteristic of empathy tends to lead to the assumption that utopian outcomes are possible for all. Something will save us all before we reach the cliff edge!
One might ask what relevance the above paragraph has to wildlife conservation. I tend to believe that many armchair supporters and financial backers of what they believe to be conservation have utopian values reached though empathy. The application of empathy to adjudicate on conservation policy is, in my opinion, misdirected and dangerous.
In large part, it explains their overwhelmingly protectionist views which are in stark contrast to those typically held by rural dwellers in both Africa and even in the rest of the world, developed or otherwise. The failure to accept the necessity of culling (or “harvesting”) surplus individuals of some species puts the long-term sustainability of protected habitats at serious risk. Protectionists prefer to believe that nature can take care of surpluses in a benign fashion without human interference.
They can’t necessarily explain how or what is involved when animals are forced to self-regulate their populations. It is sufficient to know that they can and, if it’s natural, it must be OK. Often ignored in this pattern of thought is the fact that man is part of the animal kingdom and, before the days of protectionism, acted as a very significant predator of other species.
Critics of culling frequently like to use science for advocacy and suggest that, when man culls, he interferes with proper genetic selection and weeds out the wrong animals while nature, by starving them, apparently only weeds out the weak. They further suggest that when it comes to morally repugnant “trophy” hunting (“killing for fun”), the situation is worse because one is clearly killing those individuals with the best secondary sexual characteristics which are, apparently, reliable genetic indicators of fitness.
Those making this genetic case, which is not readily supportable by any strong scientific evidence, would probably be appalled by any suggestion that there was any heritable component to human intelligence and its potential survival value despite there being, arguably, better evidence. If animals aren’t all born equal, how can it be the case that all men are deemed to be? One might equally counter-argue that social justice and a welfare state are reversing evolutionary direction and leading to an inferior human gene pool.
Before leaving this sub-section of the debate, I think it is worth questioning WWF’s assertion that the planet can only sustainably accommodate 3 billion humans at first world standards. If correct, the future for humanity is, indeed, dire and all hope for a better outcome will be extinguished. It is scarcely surprising, therefore, that the message is ignored.
The prospect is hardly improved by contemplating what Hardin had to say on the subject. He was at pains to point out that it was only “cultural” carrying capacity that is currently constrained by ecosystem services. If we were to dump most of the benefits that technology and culture have made possible, we could sustain more people, but only by moving towards a subsistence lifestyle. Perhaps, the increasing numbers of people becoming vegetarian may be an indicator that, at least, some are trying to reduce their “planetary footprints”. I suspect that, in the case of others, a more important motivator of dietary change is empathy-induced dislike of killing other species.
It is somewhat ironic that conservationists, who laud ecotourism as a means of funding protected areas, seem not to appreciate that the harm created by the CO2 emissions associated with their international flights is possibly more potent than any good they may be creating with their visits.
For what it’s worth, I think that it may still be possible to have our cake and eat it, but only if we embrace science and technology rather than turning our backs on it. Hardin might be correct that natural sciences teach that there are finite limits to what the planet can provide. However, a supply of affordable, non-polluting and plentiful energy can unlock resources which currently appear to be reaching their limits.
In theory, we can cope with a global human population of 10 billion if we take prompt action and we can do so sustainably while, simultaneously, freeing up more land for conservation of other species. Given that we’ll have a population of at least 9 billion by 2100 (absenting catastrophic disasters) even if we cut fertility to replacement rate now, we certainly have to hope so. I would add one caveat.
I don’t believe that any source renewable energy or combination thereof can match the energy criteria needed, however much we attempt to reduce our emissions and hence, probably, our lifestyles. Thus, elected politicians, who indulge in virtue signalling by subsidising renewable energy, are, in my opinion, putting our futures at risk.
Power generated by nuclear fission, using technology that is currently understood and developed, seems to me to be the only plausible route both for our grandchildren’s salvation and for that of wildlife. Thus, from my perspective, the rapid roll-out of nuclear energy is a vital conservation goal.