By this argument, no human generation could ever decide that protecting a species is more trouble than its worth and so let it become extinct, as there would always be the theoretical possibility of a future generation that might regret this choice. Every choice we make as a generation constrains and widens the choices available to future generations. If we protect endangered species and therefore limit agricultural and housing land (to protect their environments) we deny future generations more plentiful food supplies and better housing. We may even deny the existence of more humans in the future by not having enough food to feed a population which could grow faster if the food supply was greater. We cannot allow the remote possibility of future regret to cause us to take actions which a great many people will 'regret' in the present.