On Cruise Ships and Vital Needs [Part 2]

Cruise ships are a common target of ire. In my last article, I turned to consider whether the climate crisis provides yet another reason for us to refrain from taking such journeys. In the process, I introduced Henry Shue’s distinction between subsistence emissions (those that are necessary for the fulfillment of our vital needs) and luxury emissions (those that are not). According to Shue, while we might have a moral obligation to reduce our luxury emissions, we have no such obligation when it comes to our subsistence emissions.

All of this means that our specific climate-based obligations really come down to what things count as “vital needs.” As I noted previously, it seems that these needs must be either subjective (that is, determined entirely by the preferences and desires of the individual) or objective (that is, essential for all people, regardless of their desires and preferences). But problems arise with both approaches. A subjective list would be far too permissive – allowing someone to count anything as a vital need. An objective list, on the other hand, might be too restrictive – failing to include things that are very important for some, but not for others.

I spend a lot of time thinking about how this distinction applies to our choice to have children. In a now infamous paper, Paul A. Murtaugh and Michael G. Schlax demonstrated that when an individual in the US chooses to have a child, they add an additional 4720.5 tonnes of CO2 to the atmosphere. That’s around 59 tonnes per year spread over the parent’s 80-year lifespan. To put this number into perspective, that’s enough carbon to undo the work of 684 teenagers who choose to adopt comprehensive recycling for the rest of their lives. Put simply, having fewer children is one of the most effective ways that we can combat climate change. But are we under a moral obligation to do so? If having children – i.e., procreation – is a vital need, then the answer is “no.”

But would procreation appear on an objective list of vital needs? It seems not. More than 20% of US adults are now “childfree by choice,” meaning that having children clearly isn’t a vital need for these individuals. In fact, for many of them, not having children might very well be a vital need. Does this mean that the emissions associated with having children are luxury emissions? Elsewhere, I’ve argued that they are. But maybe it’s more complicated than that. It remains true that procreation is enormously important for some, such that their lives will be severely diminished if they never have children. How can this be reconciled with the aforementioned fact that, for some, the exact opposite is true?

One way is to approach the relevant vital need in a more nuanced way. Perhaps the objective vital need in question isn’t simply “procreation,” but rather “creating the kind of family you want.” Couched in this way, this vital need accommodates both those who don’t want children (and for whom “the kind of family you want” is small) and those who do want children (and for whom “the kind of family you want” is somewhat larger).

A similar approach can make sense of the education example I provided last time. It’s not that our (objective) vital need is a specific kind of education, but rather the education that one needs to live their desired life. For some, this might only necessitate a K-12 education. For others, it might require trade school. For yet others, it might require a trio of doctorates.

In a sense, what we’re now talking about are objective vital needs that are phrased in broad enough terms to accommodate the subjective desires and preferences of the individual in question.

Such a solution seems promising – until we realize that introducing even this amount of subjectivity might see the return of the “overly-permissive” concern. What do we make, for example, of a couple for whom “the family they want” contains fifteen children? Must we count the emissions of all of these children as subsistence? Or do we need to introduce some kind of objective limit? Must we – in light of the climate crisis – modify the vital need in question to be something like “creating the kind of family you want, up to a reasonable size”? Perhaps this is a necessary move. But then how do we determine precisely what this reasonable size is?

These are difficult questions – and ones that take us far from our starting point. What’s important, however, is that even if we adopt a view of vital needs that is semi-subjective (as we did above), there is little chance that “going on a cruise” will appear on that list. And if that’s the case, then it remains the case that (as we first suspected) we are, most likely, under a moral obligation to refrain from taking such emissions-intensive voyages.