Eco-footprinting.... starts from a series of simple premises:
* People remain integral components of the ecosystems that sustain them;
* Most human impacts on ecosystems are associated with energy and material extraction and consumption (all economic activity has material consequences);
* Many energy and material flows are readily measurable and can be converted to corresponding productive or assimilative ecosystems areas;
* There is a finite area of productive land and water ecosystems on Earth.
Via Susan Davis Cushing