In his essay "The Land Ethic", naturalist and conservationist Aldo Leopold¹ argued that American, if not global, society needed further ethical development to account for human treatment of land. Leopold's argument began with ancient Greek and Hebrew notions of morality, and he pointed out that in ancient Greece it was ethical to kill slaves because the killing of a slave was simply the "disposal of property". Later, the humanity of slaves was recognized sufficiently that killing of a slave was considered unethical. Ownership of slaves nonetheless remained legal and was practiced in America by some of the most admired public figures. Finally, but only about 150 years ago, the ownership of humans was made illegal for ethical reasons in most countries. Thus the ethics of the ownership and treatment of humans have changed greatly over the centuries.

    Similar changes in ethics have happened with regard to treatment of animals. In most European cultures before this century, few formal ethical restrictions existed to prevent cruelty to animals. Animals were viewed as property that could be disposed of by their owners as the latter saw fit. Today, most states and western countries still view domesticated animals as "owned", and they allow owners to cause animal death at any time convenient to the owner. However, laws now exist to prevent exceptionally cruel treatment of animals, and especially of horses and household pets². Laws do not prevent the eating of domesticated animals, but ethical considerations increasingly keep many people from doing so. Thus the ethics of the ownership and treatment of animals have changed, but not as much as the ethics of the ownership of humans.

   Leopold's argument was that, by comparison, ethics with regard to land remain very primitive. In western societies, land is owned. In fact, the legal system of the U.S. so much assumes land ownership that it is almost inconceivable that a piece of land not be owned by an individual, a corporation, or a governmental entity. The notoriety of "the tree that owns itself" in Athens, Georgia, is the exception that proves this rule of ubiquitous land ownership by humans, in that the self-ownership of a few square feet of land in the U.S. (or its ownership by a tree) is such a peculiarity that it merits mention in tourist guidebooks.

   Traditionally, owners of land have been allowed to perpetrate almost any act to the land that they owned. Today, since the time that Leopold wrote, laws do exist that restrict some treatment of land. However, those laws exist only to protect the interests of other humans, their property, and their resources. For example, some jurisdictions have laws prohibiting soil from washing into rivers and thus fouling human water supplies, laws prohibiting dumping of wastes that foul groundwater under other tracts of land, and laws prohibiting presence of junk that diminishes the aesthetic value of nearby tracts of land. However, all these laws have been enacted only to protect the interests of other humans, and not to protect land.

   As a result, owners of land remain legally free to perpetrate a variety of violences to the land itself. They are free to remove all trees, other plants, and animals, thus stripping the land of its ecosystem. They are free to farm the land with practices that lead to massive erosion of its soil³. They are free to remove and sell all the topsoil or even all the soil, stripping the land of its capability to grow anything. They are free to seal the land surface with concrete or asphalt, precluding the influx of rainwater to renew groundwater supplies that had previously been present for millenia. With the acquisition of a permit, they are free to blast out the rock under the soil and sell it, leaving a hole in which the depth is limited only by the available technology, and leaving a waste pile or tailings pile that may cover even more land. These acts take place every week, if not every day, in every county of every state of the U.S.

   Most Americans would respond that "Yes, that's economic development", or "We don't hear any cries of pain from the dirt that you're so worried about". Those are true statements. Less cynical Americans might respond, "We've set aside parks as parcels of unexploited land". That's true too. However, to expect the government to solve the problem with a few parks ignores the responsibility of individuals to be involved in the preservation of the land and its ecosystems. That responsibility can come from an ethic that says that land, like humans and like animals, is not something inevitably to be owned and to be disposed of at its owner's whim.

   If philosophical arguments aren't sufficient grounds for a land ethic, there are practical arguments too⁴. Practices that destroy natural land will negatively, if indirectly, impact humans. Covering the land with buildings and parking lots prohibits influx of rainwater to renew groundwater supplies, and the resulting increased runoff of rainwater causes flooding far beyond what would result in a natural system. Erosion leads to muddy rivers that foul surface drinking water supplies; one need go no further than the red rivers downstream from housing developments in the southeast to see that. Temperatures changes are greater and winds are far stronger where forests have been cut, leading to higher climate control costs and greater damage from storms. Forests also act as sinks for CO₂ produced by our burning of fossil fuels⁵. Erosion of farm fields clearly diminishes agricultural productivity, leading to higher food costs, lower land values, and ultimately to food shortages. Urban development has been shown to create "heat islands" that cause violent thunderstorms⁶. Combining these and many more physical effects with the known psychophysical effects (for example, just looking at trees lowers the blood pressure of most humans) presents a persuasive argument that land conservation and stewardship favors, rather than disfavors, human development in the broadest sense.

   In short, Aldo Leopold's argument that humans are part of a biological community dependent on healthy land is as strong today as it was fifty years ago. We have developed ethical principles regarding our treatment of other humans in order to maintain the stability of our social communities. Leopold would argue that we likewise need to develop ethical principles regarding our treatment of land, and a sense of land stewardship, to maintain the biological or ecological community in which we inevitably live.