Land Use on Mars

National space agencies, including NASA, ESA, the Indian Space Agency, and the Chinese space program, all have Mars in sight. Current Mars exploration programs all have human spaceflight in mind for the near future, and eventual plans for exploration often turn to thoughts of permanent settlement or colonization. Several private corporations have also declared their intent to visit, or even colonize, Mars within the next several decades. Whether or not they succeed in their planned time frame, it seems evident that humans have their eyes on Mars.

The patterns of history show us plenty of examples of how land resources have benefited the few over the many, or how conflict over scarce land resources have led to violence and war in extreme cases. Even more fundamentally, the amount of land on a planet is finite, but it is only recently that the practice of homesteading became impossible on Earth. Mars holds the potential for settlers to once again lay claim to open areas of unclaimed land, but is this the best policy for using the resources of space?

In a book chapter published in the Springer edited volume Human Governance Beyond Earth: Implications for Freedom, I discuss my research and thoughts in an effort that will lead “Toward a Sustainable Land Use Policy for Mars.” I discuss the constrains of existing treaties governing the use of space resources, and I present a few possible alternatives for what a land use policy on Mars might look like.

An “Ecological Compass”

Only recently have humans gained the capability to willfully and technologically manipulate the environment on a global scale. This sort of planetary engineering includes present-day geoengineering proposals to counteract anthropogenic climate change by reflecting away a fraction of incoming sunlight. Although such a feat seems technically achievable, whether or not we should engage in such geoengineering is a question of ethics. Other, more futuristic, kinds of planetary engineering include plans for terraforming Mars to increase global temperatures and make the red planet habitable for Earth life. For terraforming as well, the technology for terraforming may be available today, but whether or not we should deliberately modify another planet is a question of ethics.

I recently published a paper in the journal Astrobiology that develops a two-axis framework for comparing different views about how we value organisms, environments, planetary systems, and space. The ecological compass is shown in this figure with a scale from “space” to “intelligence” along the horizontal axis. This axis is intended to represent the vast diversity of life on Earth, from humans and other animals on the far right, to microscopic organisms near the middle, to planetary systems and space on the far left. The vertical axis of the ecological compass contrasts two types of value: instrumental value and intrinsic value. Instrumental value describes the usefulness or purpose that an object, organism, or system provides; for example, a logger may assign instrumental value to trees that are grown for lumber. Intrinsic value describes the an object, organism, or system as valuable for its own sake; in this sense, a hiker may view a tree as valuable simply by virtue of its being a tree. With this two-axis system, we can describe and compare various attitudes toward nature and their implications for planetary engineering.

An anthropocentric view, which assigns instrumental value to all life other than humans, may find no environmental objection to planetary engineering. This is because anthropocentrism is only concerned with the effects of planetary engineering on humans. A zoocentric (or ratiocentric) framework extends intrinsic value to animals and gives at least some consideration to how human actions affect these organisms. As such, zoocentrism suggests that some consideration should be given to the effects of geoenginering on non-human animals. Likewise, a macrocentric viewpoint considers large, visible organisms as intrinsically valuable, while a microcentric viewpoint considers even microorganisms to possess intrinsic value. Under these ethical frameworks, the decision to terraform a planet such as Mars will depend upon the organisms that are already inhabiting it. Finally, a cosmocentric framework places intrinsic value across the entire biological spectrum from intelligent creatures and microorganisms to planets and space. This suggests that a cosmocentric ethical framework would refrain from any sort of planetary engineering because a planet is valued for its own sake.

This ecological compass is intended to be used as a tool for discussions of human valuation of nature. As a tool it cannot provide the answer to whether or not we should engage in planetary engineering, but it can at least help us raise important questions about how we value nature in advance of any decisions.

Think Before Geoengineering

Geoengineering describes the large-scale use of technology to manipulate the Earth system. Geoengineering strategies are currently gaining attention as possible ways to avert the undesirable consequences of climate change. One of the most plausible geoengineering ideas is known as “solar radiation management”, which proposes to offset global warming by reflecting away a portion of incoming sunlight. The easiest way to do this would be to fly a bunch of airplanes into the stratosphere to release sulfate aerosol particles. These particles would reflect away sunlight and, perhaps, could help us to avoid what would otherwise have been a climate disaster.

In a recent paper published in Ethics, Policy and Environment, on which I am a co-author, we discuss how scientific study of geoengineering is intertwined with the ethics of geoengineering. For example, if we decide that geoengineering is a fundamentally bad idea–perhaps because it could cause political turmoil or perhaps because we disagree with the idea of intentionally altering our atmosphere–then we should move on to other potential solutions to the climate problem. If we do decide that geoengineering is at least worth discussing, then we need to be careful to identify when scientific decisions are also ethical decisions. An experiment that seeks to test the effects of geoengineering over a small region will necessarily affect the local environment; whether or not such an experiment should occur is a question of ethics, not science. If geoengineering remains on the table, then these ethical issues carry as much importance as the scientific know-how. Perhaps we should therefore create an international board for the ethical, social, and legal implications of geoengineering so that our science doesn’t get too far ahead of our conscience.

Climate Change and Skepticism

Evidence for anthropogenic climate change continues to build, but even some academics retain a skeptical attitude toward the radical claim that humans are significantly changing the climate of Earth. In a recent article published in Science and Engineering Ethics, on which I am co-author, we discuss several issues raised by climate change skeptics.

The first issue we address is an observed decline in global temperature from 1943 to 1975, which resulted from an increase in emission of sulfur aerosol from industrialization that scattered away sunlight and cooled the surface. The second issue is the use of ice core data to reconstruct ancient climate data, which requires the careful extraction and characterization of air bubbles trapped within the ice. The third issue concerns the role of clouds in climate change, which indeed is one of the greatest sources of uncertainty regarding climate change. We also discuss other key uncertainties, such as the sensitivity of surface temperature to greenhouse gas concentration, the contribution of glacier melt to sea level rise, and the regional effects of climate change.

What society should do about climate change is fundamentally an ethical question. The answer to this question depends on our ethics–that is, on what we think is right and wrong or good and bad. Some skeptics might argue that we should not address climate change because of the expense involved in mitigation or adaptation, but the direct and indirect damages from climate change will be costly to businesses, governments, and individuals. Based on these cost considerations as well as a regard for human civilization in the future, a strong ethical argument can be made that society should prioritize reducing greenhouse gas emissions to reduce how much the climate will change.