The Rock Ethics Fellows recently met to discuss ethical issues related to sustainability, particularly the sustainability of certain human practices and systems. In general, a practice is thought to be sustainable if it does not compromise the ability of future generations to lead economically, socially, and environmentally decent lives.
The discussion focused on what is required in order to live sustainably. This included questions about human population. Although it is unclear what the "carrying capacity" of the planet is for human population, there is presumably some limit to how many humans can live sustainably on the Earth. However, it is unclear whether or how population growth should be curbed, as doing so might involve violating certain rights of various persons.
The topic of how to manage finite resources was also considered. It was suggested that transitioning to renewable energy sources would be much more sustainable than current energy sources, most of which rely on limited stores of fossil fuels.
Finally, the issue of sustainability was connected to social justice. In particular, ethical sustainability seems to depend on the notion that present persons have duties to future generations. These duties are thought to require currently living persons not to deplete the resources that might be needed by future persons, as well as to protect the environment from degrading in ways that could harm the well-being of such future persons.