During our exploration of each previous lesson, we have learned about many of the factors that contribute to the ongoing destruction of our environment. In our final lesson, we will make a holistic appraisal of the impact that each of them has on the natural world around us. We will begin by estimating the human impact, or ecological footprint, that each of us leaves on our planet. This footprint measures how much nature we consume. It shows how much productive land we use in order to produce all the resources that we consume and absorb all the wastes that we produce.