When I got to the editing stage of the manuscript for my upcoming book, Off-Earth: Ethical Questions and Quandaries for Living in Outer Space, I quickly realized that the third chapter, about how to choose which humans to send to a space settlement, was A Problem. It was just way too long compared to the other chapters.
So the red pen came out, along with a few thousand words from Chapter 3. But there was one section in particular that I couldn’t just throw away completely, because I love the topic. So here’s a deleted scene from Off-Earth, about the ethics of bringing non-human life along with us to settle space.
Non-Human Life in Space Settlements
Choosing which humans to send to a space settlement is clearly a daunting and complex task. But there is an additional selection process we’ll need to consider: what kind of non-human life should we bring with us? We’ll likely need to bring a variety of plant life, as both a food source and an oxygen-generating mechanism. The choice of which plants to bring will be a matter for the botanists, nutritionists, and agriculture experts to discuss and decide. If we’re still using animals for food, we might bring livestock, although the scarcity of space, energy, and water in an off-world settlement may limit us to insect-based protein sources.
But what about bringing animals for other uses, for example, as companion animals? Psychological research has demonstrated that pet ownership can benefit the owner’s mental health. Living in space poses a number of psychological challenges, thanks to the isolation, darkness, physical stressors, and ever-present danger. Bringing along cats or dogs for pets might help to counteract some of the psychological burdens of the space environment. A completely unscientific poll of my friends and family has revealed that the number of people willing to live in space increases dramatically if they are allowed to bring their pets along. Less anecdotal research has shown that spending time in nature can also improve our mood as well as our ability to focus on tasks, so perhaps the plant life brought to space will serve a third purpose, as a support for the settlers’ mental health.
Humans have also been using animals as a source of labor for thousands of years. It’s unlikely that we’ll employ animals for the same tasks in enclosed spaceships and habitats, where we’ll have little use for hunting dogs, oxen, or horses. On the other hand, anywhere that humans go, rats, insects, and other pests are sure to follow. Rats spread across the globe following human trade routes and colonization by hitching a ride on caravans and ships, and in modern times they even infest airplanes. If they eventually manage to sneak aboard rockets, as well, cats may play a vital role in protecting the food stores of our descendants in space.
But before we bring animals along for labor, we should reflect on the ethics of drafting creatures for space travel who have no concept of space. Many of the ethical concerns regarding animal labor in space can be raised here on Earth, but space poses additional risks and stresses on the animal. Space is not the natural environment of any Earthling, but at least the humans going to space are volunteering to leave their gravity, atmosphere, ecosystem, and fellow humans behind. Does removing an animal from its home planet in order to exploit its labor constitute cruelty, or is it no different from our current animal labor practices on Earth?
We may find ourselves with another motive for bringing non-human life to space with us, besides as a source of comfort and labor. In the scenario where the habitability of the planet is threatened by some catastrophe, we may hope to preserve as much of the Earth’s biosphere as possible by using spaceships as Arks, transporting species to a new environment where they can survive. We would somehow have to decide which species to bring with us, and which to allow to go extinct, and whether to try to save as many species as possible, or just a diverse, but representative sample. We’ll also have to consider the stability of the ecosystem we create in space. We wouldn’t want to bring too many predator species and not enough prey, for example.
Managing ecosystem stability already poses a huge challenge on Earth, where we struggle with invasive species, soil depletion, and loss of biodiversity. Often our own attempts to manipulate the local ecosystem only make things worse. One of the most notorious examples of this was the introduction of cane toads into Australia. In the 1930s, sugar cane farmers in Australia were struggling to control the native cane beetles, who would bury their larvae underground where they could devour the roots of the sugar cane. A government agency known at the time as the Bureau of Sugar Experiment Stations decided to try importing cane toads from Hawaii to feed on the cane beetles. These toads, the largest in the world, are voracious eaters, prolific breeders, and poisonous in both their tadpole and adult forms. Most of the native predators that attempt to prey on cane toads, such as freshwater crocodiles, can be killed by the toads’ poison. Meanwhile, the cane toads gobble up the food supply of native insectivores and deplete the populations of valuable insect species like dung beetles. As a final insult to the Bureau of Sugar Experiment Stations, there is no evidence that the cane toad has had any effect on the population of cane beetles. The cane toad is only one of many examples of our failures to outsmart an established ecosystem on Earth. Creating a new ecosystem from scratch in space from the survivors of a global catastrophe will be even more complex, not to mention carrying higher stakes.
We can’t (and shouldn’t) avoid taking non-human life with us to space, not if we want to eat. The list of species we bring is likely to go beyond those needed for our food supply, if only because I have trouble imagining humans building a new branch of civilization that doesn’t include dogs. But to minimize the risk to the species involved, including our own, we’ll need to consult with experts in biology and ecology when developing the list of non-human passengers. And we should also take the time to consider whether we are causing unnecessary harm to the animals that we decide to bring with us.