Climate Action, Environmental Action, Sustainability

Desperate Times Call For… Half Measures

The moral obligation to conserve half the Earth

Humanity’s colonisation and conversion of the Earth’s surface has brought the ecosphere to the brink of several tipping points, beyond which lies ecological collapse (Steffen et al., 2015). We risk that collapse when our impact on the Earth surpasses its carrying capacity, with grave consequences for the wellbeing of humans and animals living now and in the future. There are few signs of us diverting our course. In what van den Berg (2016) dubs the equation of stupid, our impact is derived from our population size multiplied by our average material footprint – the area of the Earth required for the provision and reabsorption of all that we consume. Both our population and footprint are increasing, as we convert more and more land to intensive agriculture to feed the growing population, pushing more species to extinction. The great irony is perhaps that not only do we not need inflated westernised consumer lifestyles to survive, we also do not need them to be happy (Jebb et al., 2018). We don’t need such a large footprint, and we cannot sustain it.

Setting aside half of the earth’s surface for nature ought to be our ultimate collective goal, and one supported by a diversity of ethical standpoints. The great evolutionary biologist and father of sociobiology, E.O. Wilson, calculated[1] that in order to prevent an ecological collapse, we need to reserve half the Earth’s surface for the other species we share it with (Hiss, 2014). His equation has become the basis for the Half Earth Project, the largest land reallocation and governance proposal in history (Ellis and Mehrabi, 2019).

“With science at its core and our transcendent moral obligation to the rest of life at its heart, the Half-Earth Project is working to conserve half the land and sea to safeguard the bulk of biodiversity, including ourselves. “

E.O. Wilson Biodiversity Foundation, 2021

This mission statement reveals a strong moral argument based on a duty to humans, other species, and ensuring “the health of our planet for future generations” (ibid). Perhaps in response to criticisms of conservation as being all too often exclusionary of people (Nijhuis, 2021), Half Earth is at pains to clarify that it does not aim for the eviction of communities, but includes people in its plans for wild areas and “honors the wisdom of the traditional owners of the lands and waters we aim to protect and their ancient ways of seeing and experiencing nature” (E.O. Wilson Biodiversity Foundation, 2021).

Half Earth has influenced the cli-fi literary genre, with some writers imagining how such a future might look. Kim Stanley Robinson’s Ministry for the Future (2020) sees the Earth teetering on ecological collapse mid-century. (Spoilers) While disasters and suffering reach unprecedented scales, they are partly reined in by the rewilding of half the planet, assisted by a global quantitative easing scheme using a carbon coin which compensates rural communities that agree to abandon their lands and indigenous peoples that care for others. A new ecological spirituality arises and aids in a rebalancing of lives with nature and simplicity, and a global day of celebration, Gaia Day, is instituted.

“If […] we protect half the global surface, the fraction of species protected will be 85%, or more. At one-half and above, life on Earth enters the safe zone.” (E.O. Wilson Biodiversity Foundation, 2021).” [1] 

Moral obligations, Kant, and animal rights

In mentioning a ‘transcendent moral obligation’, Half Earth is explicitly espousing a deontological moral duty. Immanuel Kant, the most influential deontological philosopher, argued that the fact of every individual’s personhood and inherent dignity creates a set of universal ethical rights and obligations to be adhered to (Munro, 2020). According to Kant, the most fundamental of these obligations is to never use another human instrumentally, instead respecting their intrinsic value. Deontology has provided the basis for the most common universal ethical codes, such as the ten commandments and the universal declaration of human rights; the latter being particularly aimed at protecting human dignity. Although Kantianism stresses the reason for an action rather than the outcome, its fixation on individual dignity provides a strong basis for the conservation of ecosystems. In the time since Kant’s writings, we have come to understand how utterly dependent we as a species and a society are on the balance of the Earth system and the species interactions therein. It is a simple matter of understanding that human dignity is not separate from but dependent on these ecosystems, and therefore a contemporary perspective on Kantianism yields a moral obligation to preserve ecosystems and the human dignity that rests upon them.

Such an updated Kantian ethic includes animal rights and draws on developments in our understanding of animal cognition. Kant saw the ability to reason as what defines personhood. He declined to extend any intrinsic value to non-human animals based on their perceived inability to reason, thereby relieving us of any moral duty to them. And yet Kantianism has provided the basis for the animal rights movement, primarily through the work of Tom Regan. In The case for Animal Rights (1983) Regan argues that animals are the subjects of a life just as humans are; that this grants them an irreducible inherent value; and that it is therefore an act of justice to treat animals kindly. The deontological argument for animal rights has been strengthened in recent years by research showing that a wide variety of animals, including elephants, chimpanzees, ravens and lions, engage in rational decision-making (Buckner, 2019). Following the argument to its natural conclusion – animals have the right not to be used instrumentally just as humans – we arrive at abolitionism, by which animals have the single right not to be regarded as property (Francione, 1995). If humans are then morally obliged to share the planet with animals as equals, and we can assume that animal lives with dignity depend even more so on healthy ecosystems in the immediate sense than do human lives, we can conclude that we are by duty bound to relinquish a fair share, a half, of the Earth’s surface to them to live out their lives.

Counterargument and refutal

One counter argument to Half Earth is that it takes ecocentrism to misanthropic extremes. Some environmental philosophers are criticised for valuing other species over humans, such as the deep ecologist Pentti Linkola, who is generally regarded as an ecofascist for his views on human population control (). Fletcher and Büscher (2016) called Half Earth “a global programme of conservation Lebensraum”, and further criticise E. O. Wilson himself: “For all his zeal, (misplaced) righteousness and passion, his vision is disturbing and dangerous”. The social scientists are referring to the ambiguity over the question of whether people will need to move or be moved to accomplish Half Earth (Ellis and Mehrabi, 2019), and are linking this to the broader dark history of conservation itself (Nijhuis, 2021). Traditional or ‘old’ conservation operates on the principles of reserves and protected areas, with many instances of indigenous people being forcibly evicted, or worse (Hance, 2021). ‘New’ conservation meanwhile emphasises the inclusion of people and communities in protecting and restoring nature.

Fletcher and Büscher are guilty of using straw man arguments, by lumping Half Earth in with old conservation based on its emphasis on ‘protection’, and attacking Wilson for his statement that “our population is too large for safety and comfort”. In the latter case, such statements on population are common in environmental ethics, in the work of Naess, Curry, and van den Berg. Overpopulation however, in Fletcher and Büscher’s words, the “racialised bogeyman”, remains an Achilles’ heel for ecologists fearful of being labelled misanthropic, and an easy target for technocrats, neoliberals, and climate deniers to avoid confronting the equation of stupid.

Using the dualistic label of old conservation for Half Earth meanwhile is an over simplification, and shows Fletcher and Büscher’s reticence to engage with the theory. Wilson is explicit that Half Earth not only includes indigenous territories, but will likely hinge on their continued existence and growth. Echoing the research thread begun by Elinor Ostrom that provides the backbone of new conservation, Wilson has said that indigenous people are “the best protectors” of their own lands, and that Half Earth doesn’t mean removing people from land, but rather keeping land undeveloped. Wilson has pointed to the successes of community conservancies in providing benefits to people and ecosystems, such as those in Namibia, where 25 years community-managed conservancies have produced what Nijhuis (2021) calls the most successful example of conservation (including local people) known.

Utilitarian calculus and ecocentrism

Even accepting the suffering of people forcibly moved, a utilitarian calculus shows that Half Earth is an end that justifies the means. The major alternative philosophical school to deontology is consequentialism. The former regards the moral reasoning or the means behind an action as most important, the latter, the ends. Utilitarianism is the most notable offshoot and stems from the work of Jeremy Bentham. Bentham argued that pleasure should be the overall moral objective and based his philosophy on achieving the greatest pleasure for the greatest number. This extended to reducing the suffering of the majority, which was later prioritised over maximising pleasure by contemporary philosophers such as Peter Singer. Utilitarians perform a calculus of sorts to measure actions in terms of their effect on the overall balance of pleasure or suffering in the moral circle. Creating the half Earth will create winners and losers (Ellis and Mehrabi, 2019), but the ends will justify the means if we measure using a utilitarian calculus that considers future humans. The choice is between the suffering of those moved from their land, and the untold suffering as a consequence of business-as-usual and ecological collapse. Let there be a home on Earth for us and our descendants.

Unlike Kant, Bentham saw intrinsic value in non-human lives, and so utilitarianism opens the door to the moral imperative of reducing animal suffering. Singer’s work has built on this, expanding the moral circle to non-human animals (Singer, 1981), becoming the basis for the animal liberation movement. Performing the same calculus but using Singer expanded circle would massively multiply the positive effects of Half Earth, giving animals ecosystems (relatively) free of the planets most dangerous species. Let the pleasure of infinite beings living in a stable ecosphere stretch into eternity. Expanding the moral circle to include animals in this way often demands replacing an anthropocentric with a biocentric or ecocentric worldview. In Curry’s (2011) words, ecocentrism is the understanding that the ecological community is identical to the ethical community. These value animals not instrumentally but intrinsically, and equally to humans. A common criticism of mainstream conservation is its instrumental valuation of animals (Thulin and Röcklinsberg, 2020), and it would be easy for critics to level this claim at Half Earth, as Büscher and Fletcher (2016) have. One can find multiple mentions of stewardship on the Half Earth Project website, which can be interpreted as an anthropocentric and managerial approach to conservation. Wilson however is hailed as the pre-eminent champion of biodiversity, coining the term “biophilia” to denote the affinity that he feels for other species and believes is innate to all humans (Hiss, 2014). Wilson additionally chose to use phrase “transcendent moral obligation” (E.O. Wilson Biodiversity Foundation, 2021) to describe Half Earth. In Kantian philosophy, ‘transcendent’ is used to mean ‘not realisable in experience’, which differentiates between the obligation as a duty of care towards animals, and as a responsibility beyond the experiential, beyond animals as instruments – but a responsibility to them as our equals in having lived subjectivities. Therefore, we ought to share the Earth equally, in a sense: split right down the middle.

Virtue ethics and deep green theory

Green virtue ethics could inform the individual’s citizenship of Half Earth. Virtue ethics is a practice-based approach that encourages living a life dedicated to developing virtues. Ethical living needn’t be sub-conscious, but a lifelong process of examination and learning-by-doing forms virtues that help us to make better ethical judgements (website or Curry). This learning process is similar to the process one must undergo in contemporary society to reconnect with the land and nature. A green virtue ethic could help to 1) justify Half Earth to modern societies, and 2) make it possible to have at least a half-wild Earth. There are currently 7 billion of us, and as unlikely as Half Earth may be, it is even less likely than having half the Earth with no humans on it whatsoever. This demands a living-with-not-on the land. Rewilding is a conservation method and movement, and the term means different things to different people. The methodological side of rewilding is quickly superseding mainstream conservation, largely thanks to a string of successes in Europe and the USA, and provides the clearest vision of how Half Earth could be realised in practice (Liu, 2021). To many, the rewilding movement espouses values that depart from traditional shallow-green conservation by emphasising the need for a return to the land and a rewilding of the people (Monbiot, 2013). People could learn to live on and rewild the Half Earth through daily practice and examination, making their way towards a wild green virtuous character. This could look similar to the voluntary simplicity movement, whose adherents resist consumer lifestyles and seek a lower consumption and higher quality of life alternative (Alexander and Ussher, 2012). Other elements could lend themselves to instituting the Half Earth virtue ethic, such as an ecological empathy of the kind espoused by ecofeminism, or a revamped animist spirituality as Curry (2011) suggests.

Half Earth aligns with Richard Sylvan’s ( Routley) deep green theory, an offshoot of deep ecology that shares the latter’s ecocentrism and value-orientation, while differing in other ways. One of which being that it treats the human/non-human divide as ethically insignificant. This eco-impartiality allows for human use of the natural environment, only prohibiting use of too much, or too much use (Sylvan and Bennet, 1994). This distinction is important as it allows for the sustainable indigenous inhabitation and use of the Earth’s remaining wild places, which empirical evidence suggests may actually be crucial to their continued existence (Hayes and Ostrom, 2005; Artelle et al., 2019). Half Earth espouses this same view (E.O. Wilson Biodiversity Foundation, 2021), and so fits deep green theory in this regard. A second difference between deep green theory and deep ecology is that whereas Naess’ ecosophy T emphasises self-realisation and the societal implementation of its ethic as bottom-up, deep green theory stresses that individual development is not enough and must be accompanied by institutional change (Sylvan and Bennet, 1994). An ecologically virtuous society can only come about through significant individual and collective work. This calls for ambitious top-down measures, such as Half Earth. The foundation behind Half Earth operates on this principle, and rather than calling for individual virtuosity, it lobbies for political change and collaborates with all manner of bodies internationally to secure protected areas in their many forms.

Half Earth draws its ethical argumentation largely from conservation science and deontology, but could just as easily be reasoned from utilitarian or virtue ethic standpoints, as a universal ecological ‘ought’. Humanity thrives on concrete goals. Half Earth has the potential to unify a plurality of moral disciplines behind a shared goal, and to be applied universally to individuals and institutions of a global citizenship. Humanity’s actions thus far have brought us to the brink of ecological collapse, but in Half Earth, we have a vision of our shared moral obligation that if fulfilled could pull us back from the edge of the abyss.


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Brian Reilly is a twenty-something from Dublin. He is studying for an MSc in sustainable development at Utrecht University, specialising in earth system governance (ESG). He has a bachelors in biology, and a passion for restoration and conservation.

Describing himself as “a beginner in sustainability”, Brian has a fantastic online blog, which is “a work in progress… intended as a collection of some of [his] thoughts and interests from [his sustainable] journey”. Well worth checking out: WHAT’S THE SUSSTAINABILITY?

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