Two major threats to the environment lie in pollution and the squandering of living and nonliving resources. Because the United States, with only five percent of the world's population uses up over a quarter of the global resources, our ecological footprint is greater than any other nation's. This footprint is measures how much of the Earth's resources are used to support our lifestyle and to absorb the amount of waste produced. The choice of food, transportation, housing, types and amounts of energy usage and refuse disposal are some of the factors that determine the size of the footprint. If every person on the planet lived like the average American, we would need the materials from four Earths to sustain them. (Vogel, 2003, 83)
