Which of the following best defines ecological footprint?

The ecological footprint is best defined as a measure of human demand on Earth's ecosystems. This concept quantifies the environmental impact of individual or population lifestyles in terms of the amount of land and water area required to produce the resources consumed and to absorb the waste generated. It reflects how much natural capital we use and how much replenishment is needed, providing insight into sustainability.

Understanding this measure is crucial for assessing human activities, such as energy consumption, food production, and waste generation. It allows for a comparison of ecological demand against the planet’s capacity to regenerate resources, highlighting the balance or imbalance between human consumption and ecological health.

Other options do not capture the full scope of the ecological footprint. For example, a measure of atmospheric pollution focuses solely on environmental contaminants, while the number of species in a habitat pertains to biodiversity rather than human impact. The health of a specific ecosystem is related but does not specifically address human demands, which is central to the concept of ecological footprint.