Several philosophers argue that individuals have an interest-protecting right to parent; specifically, the interest is in rearing children whom one can parent adequately. Current children will have, in due course, a right to parent. Adequate parenting requires resources. We owe duties of justice to current children, including the satisfaction of their interest-protecting rights; therefore we owe them the conditions for rearing children adequately in the future. To engage in permissible parenting they, too, will need sufficient resources to ensure their own children's future ability to bring up children under adequate conditions. This reasoning goes on ad infinitum and entails that each generation of adults owes its contemporary generation of children a duty of sustainability: each generation must pass on to the next at least those resources that are necessary for sustaining human life indefinitely at an adequate level of wellbeing.
The global distribution of natural resources plays an important part in discharging the duty of sustainability. Currently there are several competing proposals for achieving a more just distribution of natural resources, only some of which seem compatible with a duty of sustainability as defended here. Hillel Steiner's Global Fund taxes, premised on the principle of self-ownership and the choice theory of rights is incompatible with the belief that children have rights and hence that they can be owed duties of justice. Thomas Pogge's Global Resources Dividend does not put principled restrictions on the use of natural resources and hence lacks a guarantee that enough will be left for the use of future generations. Paula Casal's Global Share recommends progressive taxation on both ownership and use of natural resources and is designed with the explicit aim of minimising environmental damage. The last proposal seems the most compatible with the duty of sustainability that I defend.
