Why should the planet’s natural resources be preserved? Some philosophers believe that natural resources have instrumental value. Instead of being valuable for their own sake, their value depends upon what humans (and possibly other sentient beings) can do with them. While some natural resources have instrumental value for nearly all of us, others have less value. We all need stable access to safe drinking water as no one could survive for more than a day or two without it. However, it is not the naturalness of the water that matters. We could produce artificial freshwater from desalinated seawater, although this is an expensive and energy intensive process.
Other philosophers argue that nature has non instrumental value. On this view, nature is valuable for its own sake, irrespective of its instrumental value to us. The moral value of a natural resource such as freshwater, oil, or the poisonous plant Mandragora officinarum does not depend on the health, welfare, or monetary values we can obtain from those resources. All these resources, and perhaps entire ecosystems, are valuable for their own sake.
The “tragedy of the commons” teaches us that there are situations in which the market will fail to reach what many would consider to be morally acceptable solutions. Fully informed and fully rational decision makers sometimes reach solutions to environmental problems (as well as many other types of problems) that are worse for everyone. Environmentalists appeal to this example for explaining the need for regulations that control the market forces.