Carbon Footprints

by Jeremy Cohen Hoffing May 2, 2010

Excessive shopping, acquiring, and consuming take a huge toll on our planet. The Global Footprint Network calculates the Ecological Footprint of various countries and of the earth as a whole. It arrives at the Footprint by calculating the use of both natural resources and ecosystem services like climate moderation and water cycles and then figuring out how much land would be needed to support this use. Conceived in 1990 by Mathis Wackernagel and William Rees at the University of British Columbia, the Ecological Footprint is now in wide use by scientists, businesses, governments, agencies, individuals, and institutions working to monitor ecological resource use and advance sustainable development.

Globally, the Global Footprint Network reports that we now consume the resources produced by the equivalent of 1.4 earths per year. That’s 40% more earths than we have! It now takes the earth one year and five months to regenerate what we use in a year. The planet produces a certain amount of resources each year. We’re not only using all of them, but we’re dipping into the store of resources that have been accumulating since the earth began. Americans are the number one consumers, and if everyone in the world were to live the lifestyle of an average American, we’d need FIVE planets!

The National Footprint Accounts track human demand for ecological services in terms of six major land use types (cropland, grazing land, forest land, carbon Footprint, fishing grounds, and built- up land). With the exception of built-up land and forest for carbon dioxide uptake, the Ecological Footprint of each major land use type is calculated by summing the contributions of a variety of specific products. Built-up land reflects the bioproductivity compromised by infrastructure and hydropower and forest land for carbon dioxide uptake represents the waste absorption of a world average hectare of forest needed to absorb human induced carbon dioxide emissions, after having considered the ocean sequestration capacity. The Ecological Footprint calculates the combined demand for ecological resources wherever they are located and presents them as the global average area needed to support a specific human activity. This quantity is expressed in units of global hectares, defined as hectares of bioproductive area with world average bioproductivity.

By expressing all results in a common unit, biocapacity and Footprints can be directly compared across land use types and countries. Demand for resource production and waste assimilation are translated into global hectares by dividing the total amount of a resource consumed by the yield per hectare, or dividing the waste emitted by the absorptive capacity per hectare. Yields are calculated based on various international statistics, primarily those from the United Nations Food and Agriculture Organization (FAO ResourceSTAT Statistical Databases). Yields are mutually exclusive: If two crops are grown at the same time on the same hectare, one portion of the hectare is assigned to one crop, and the remainder to the other. This avoids double counting. This follows the same logic as measuring the size of a farm: Each hectare is only counted once, even though it might provide multiple services.

The Ecological Footprint, in its most basic form, is calculated by the following equation:

EF = D (ANNUAL)  / Y (ANNUAL)

where D is the annual demand of a product and Y is the annual yield of the same product.
Many low-income countries have an abundance of natural resources, yet their populations often suffer first and most tragically when humanity’s demand on the biosphere exceeds what the biosphere can renewably provide. Countries in Africa, Latin America, and South East Asia have some of the lowest per capita Ecological Footprints
in the world--in many cases the flow of usable resources from these Ecological Footprints is too small to meet basic needs for food, shelter, health, and sanitation. For these regions to reduce poverty, hunger, and disease, their access to natural resources must increase. Yet the growing population and the rest of the world’s escalating resource consumption are making this increasingly difficult to manage in a sustainable manner. If low-income countries are to make advances in human development that can persist, they will need to find approaches that work within the Earth’s ecological budget.
When utilizing moderate projections of UN agencies for 2050, based on slow population growth and slight improvements of people’s diet, human demand would be twice of what Earth could provide. Moving energy systems away from dependancy on fossil fuels, preserving bioproductive areas, and restoring unproductive areas would go a long way to reducing this demand, but even optimistic forecasts are still not sufficient to bring demand within the biological capacity of the Earth. Therefore, relying on a growing level of consumption to attain sustainable well-being for all is unrealistic, especially given the increasing global population. While technological improvements can certainly help alleviate the strain placed on the environment, placing complete reliance on continued improvements in the future does not represent good planning. Worse, the accumulated ecological debt from decades of ecological overspending is likely to start decreasing the biosphere’s regenerative capacity at the same time we are increasing our demands on it. Realizing the “right to develop” of all countries requires constructing new development pathways that place much less strain on the global environment than have historically been the case.

Resources

Lenoard, Annie. The Story of Stuff. 2010. Free Press: New York.

Global Footprint Network, Research and Standards Department. Ecological Footprint Analysis 2009.