Human Footprint

Humans have influenced 83% of Earth’s surface.
This finding from the Human Footprint Project, a major initiative of the Bronx Zoo-based Wildlife Conservation Society, is based on analysis of four factors that have the most impact on wildlife and wild lands: population, travel routes, land use, and lights.

Discuss: Does this number seem like a lot or a little? Why? Some areas are more vulnerable to human influence than others—why might this be?