Dr. John Vann, Department of Marketing
Green Initiatives Coordinator
February 2003

A new way of measuring the environmental impact of human activity is called "footprinting."  The approach assesses how much biologically productive space (Earth's natural capital) is required to support a given population with its lifestyle -- that is, to provide the food, energy, water, materials, and other resources to support a given lifestyle and to absorb the liquid, solid, and gaseous byproducts of that lifestyle.  Space for structures, highways, parking lots, toxic spoil, and other applications are part of the footprint. A nation's footprint may reside partly outside its borders.

Redefining Progress says the 1999 global per-capita biologically productive space was 4.7 acres while the per-capita footprint was 5.6 acres, so our collective footprint currently exceeds the Earth's ecological capacity. This is like living off the principal of an investment instead of just the interest. They also report that in 1999, the average footprint (in acres) for the United States was 24, Canada 17 (30% less than the U.S.), U.K. 14, Italy 9, Japan 11, and China 3.9.

As an example, Ball State's paper-use footprint includes, but is not limited to the acreage for growing trees to make the paper. Our energy-use footprint includes the acreage for trees needed to absorb the CO2 emissions generated by burning coal for energy.

We may reduce our footprint by choosing carefully the resources we use as inputs and reducing their quantity, by making our processes more efficient, and by generating less waste that cannot be reused in another industrial or natural cycle. To find out more about footprinting and to calculate your personal footprint with the Ecological Footprint Quiz, visit