1.5 Ecological Footprint and Human Impact

Notes

An ecological footprint estimates the area of land and water needed to supply the resources a person or population uses and to absorb its wastes.

• It is measured in global hectares per person.
• When humanity's footprint exceeds Earth's biocapacity (its ability to regenerate resources), it is called ecological overshoot.
• Wealthy countries generally have larger per-person footprints than low-income countries.
• Ways to reduce a footprint: use less energy, eat less meat, drive less, reduce waste, and buy durable goods.
• The IPAT equation relates impact to population, affluence, and technology: $I = P \times A \times T$.
• Example: if a country's footprint is 4 global hectares per person and its biocapacity is 2 per person, it uses twice what its land can regenerate.