Essay on Ecological Footprint

Use the CH6 article: “Spatial sustainability, trade and indicators: an evaluation of the ecological footprint”
I would like you to define what the ecological footprint is, using a combination of class notes and the article, and then explain why the theory of an ecological footprint is good, but why can fail in practice.
Do not plagiarize. All of the information should be coming from this article and put in your own words.