Sustaining prosperity not just a local, but global scale, is a tenable goal- but to reach it, first we must value many ‘unseen’ services of nature. And second, we must reconcile that which can be sustainably supplied with what our demand is. New sources of information can help us do that. The health, diversity, and functioning of a living system affects its biological capacity (or biocapacity) to provide natural resources. Yet the goods and services that nature supplies is one half of the equation. The second half of the equation is demand. The ecological footprint is an estimate of how much productive land and water is needed to support what a person uses and discards each year.1
Personal account: The ecological footprint can be calculated for each one of us. For example, each year each of us consumes a measurable quantity of wood. There is thus an area of forest, somewhere in the world that is dedicated solely to each of us for forest products- to produce the newspaper, books, printer paper, furniture, the beams of our houses, our firewood for camping, etc. We can quantify each of the things a person uses and discards in a year, as they correspond to an area of agricultural, forest, sea and pasture needed to produce them. The total is an ecological footprint. Our daily choices affect its size. We don’t often think of it, but our choices affect lands very far away from us.
Business account: The ecological footprint can also be quantified for a given activity (for example, a vacation), or for production of an item (a table), or for the annual operations of an organization (like a company). The ecological footprint can be broken down into various parts. For example, the carbon footprint represents how many pounds of carbon dioxide were emitted while taking the vacation, making the table, or in company cars in a year. Thus it provides a quantified benchmark against which we can improve. Through application of ecological footprint indicators, we can identify the most efficient means to reduce the footprint of our lifestyles and daily operations.
National accounts: National policies on economic development greatly affect the biological capacity of a nation within it’s borders, and the ecological footprint of its residents, both nationally, and worldwide. Conscientious choices must be made, as national policies affect what a nation is going to sustain, for whom, and for how long. Using ecosystem service indexes, we can understand a broader range of ways in which a nations living ecosystems benefits the lives of its citizens. And, the ecological footprint can help us better understand how wide and a nation’s “back yard” really extends. When a nation is maintaining biological capacity, in surplus of that which its inhabitants needs, then it is considered an ecological creditor. Yet when its inhabitants are, sum total, consuming more of its biocapacity than it is producing, that nation is considered an ecological debtor. These maps show how the distribution of debt and credit has changed over time: