It is claimed that having fewer children will help reduce greenhouse gas emissions, but is it that straightforward? Eric Brandstedt looks at some of the complexities of this recommendation.

In one of the most talked-about climate change-related papers last year (see McSweeney, 2018), Seth Wynes and Kimberly Nicholas (2017) identified the most effective lifestyle choices that individuals can take to reduce their greenhouse gas emissions. The article provoked a heated debate because it makes a controversial recommendation: according to the authors, the most effective choice is to have one less child.

But is this conclusion warranted? In a recent paper, Philippe van Basshuysen and I (2018) argue that the attribution and calculation of responsibility for reproductive choices is more complicated than Wynes and Nicholas assume. In this post, I will adduce some further reasons for being wary about this result.

Their main argument was that school textbooks and official government documents fail to recommend the most effective actions. Based on a literature survey they presented “best estimates” of the carbon footprint of various individual actions and sorted them into categories based on their expected magnitude.

They identified four high-impact actions: having one less child (estimated to reduce CO2-equivalent emissions by 58.6 tonnes per year), living car-free (2.4 tCO2), abstaining from a transatlantic flight (1.6 tCO2) and eating a plant-based diet (0.8 tCO2). The actions that are typically recommended have a significantly lower impact. For example, hang-drying clothing only saves 0.21 tCO2.

The gap between the high- and low-impact actions is glaring, but what is most striking, and what sparked the debate, was how immensely more effective it would be to have one less child than any other action an individual could take. It seems individuals should simply not have children. However conscientious he or she otherwise is – having no car, refraining from flying, being a vegan – that would all be swamped by the great impact of having a child. But that is to jump to conclusions.

Consider first how the choice of having one less child is different from the other high-impact actions in that it only indirectly influences the drivers of climate change. Per capita emissions are calculated by dividing a country’s total emissions (counted either in terms of production or consumption) by its population. Having fewer children will have no direct impact on total emissions, but indirectly it may because a smaller future population can be expected to amount to less future demand for fossil fuel and other goods having a negative effect on the climate.

Thus, the effectiveness of having fewer children is dependent on the future energy system. Were we to transition to a carbon neutral economy, which is the goal accepted by most countries of the world in the Paris Agreement, the size of the future population would thereafter be irrelevant from a climate change perspective. Less demand for fossil fuel due to a smaller population would be beside the point if we had already replaced dirty old fossil fuel infrastructure with clean new renewable technology.

Now, we do not know at what pace such a transition will occur, although recent years have shown many positive signs of it picking up (see e.g. Stern 2015). But in the transitional phase, where we are, the relevant question is not whether having one less child is the most effective action to reduce future demand for fossil fuels, but rather whether it is the most effective action to accelerate and facilitate the transition. This I am sceptical of.

The actions, policies and decisions required to decarbonise the economy concern the energy system itself more so than its consumers. The challenge is to make sure that large parts of prospected fossil fuel reserves are kept in the ground. The focus should thus be on the supply-side rather than the demand-side.

In that light, an individual’s action to organise and collectivly to put pressure on phasing out fossil fuel subsidies or on divesting from fossil fuel companies may be more important than having one less child. Of course, that needs to be quantified if possible. Unfortunately, Wynes and Nicholas neglected this category of individual actions.

Another reason for scepticism about Wynes and Nicholas’ conclusion is that the individual action recommendation “to have one less child” is paradoxical in the context of sustainability.

They note that in order to stay within the emissions budget set by the Paris Agreement, per capita emissions need to decrease to 2.1 tCO2 by 2050. From the perspective of a conscientious individual, one should then already today ask oneself what actions are compatible with such a level of emission.

One soon realises that it is not just that one should have one less child, but the high-impact is true of each decision to have a child; so, one should really have no children. But if all were to reason like that, humanity would go extinct.

All but the most radical deep-ecologist would believe that this is surely a reductio ad absurdum of a conception of sustainability. If there are climate-related individual obligations related to reproductive choice, then they cannot simply be to not have children, nor can it be to have one less child if that is not elliptical of some more precise formulation.

By Eric Brandstedt


← Part 1

Eric Brandstedt is a postdoctoral researcher in philosophy at Lund University. His current research project concerns the relationship between climate ethics and climate politics. He is also interested in intergenerational justice and methodological questions in normative theorising.


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