Final answer:
A decision with fatal consequences is considered high impact on Tracy Fullerton's scale. The precautionary principle is the idea that when the effects of a human activity are poorly understood, potential harm is assumed, leading to careful proceeding.
Step-by-step explanation:
In Tracy Fullerton's scale of relative consequences, a decision that can have a fatal consequence is considered high impact. This is because the potential outcome of such a decision can result in the most irreversible and significant outcome, which is the loss of human life. Therefore, it is crucial to carefully assess and make decisions that could lead to fatal outcomes in order to prevent such consequences.
The principle that suggests when the effects of a human activity are poorly understood, we must presume that some level of harm may exist to the environment, and thus must proceed with that activity carefully is called the precautionary principle. This principle is crucial in decision-making processes that affect the environment and public health, to ensure that actions do not lead to unintended and potentially irrevocable harm.