The Ecological Footprint – Navigating Tough Decisions in a Resource-Constrained World

The following is a brief account of an address by Dr Mathis Wackernagel, to a meeting at the Law School, University of Canterbury, Monday 21 July, 2008. The meeting was organised by:

Dr Wackernagel is Executive Director, Global Footprint Network, Oakland, California.

The Ecological Footprint (EF) measures humanity’s demand on nature’s biocapacity (for more details visit It is a management and communications tool that measures how much nature we have, how much we use, and who uses what. It represents the area of biologically productive land and water a population (individual, city, country, or all of humanity) requires to provide the resources it consumes and absorb its waste, using prevailing technology.

There are three components to the measured EF of a country, according to the relative amounts of land used for them: built-up land (the smallest component); food, fibre and timber production; and carbon dioxide absorption (to correct for fossil fuel burning)(the fastest-growing component).

The global average available biocapacity is currently (2003 data) 1.8 hectares per person (with no allowance made for the needs of wild species). Staying within this figure would in principle be globally sustainable. In reality, the global EF is running about 2.2 hectares and rising, meaning humanity as a whole is currently living as if another planet’s biocapacity were available. The result is a (rising) ecological debt to Planet Earth, which will have to be paid - and the sooner, the better.

A given country’s sustainability depends upon its population and land area. Highly-populated countries with a small land area are mostly unsustainable, as are less-populated countries with high resource demands. Currently, almost half the countries in the world - the wealthy ones basically - significantly exceed sustainability limits, as measured by the EF. New Zealand’s footprint is very high, at close to 6 hectares per person, although our small population relative to the land area means the country as a whole (by this measure) is sustainable.

Dr Wackernagel addressed several policy issues in his talk. He pointed out that although climate change took most media and political attention, the greater reality facing humanity was that of resource depletion - categorised as Peak Everything, meaning not just oil, but also coal, water, soils, uranium and so on.

He felt EF should be considered as a policy indicator, alongside the better-known ones of Gross Domestic Product (GDP) and Human Development Index (HDI). All countries need good, strong tools to achieve sustainable development goals. The economic measures (eg GDP) were relevant 50 years ago, when financial capital was the principal limitation on human development (eg HDI), but nowadays it is natural capital (biocapacity - eg EF) that is the limiting factor. Governments around the world are still resolutely gluing their eyes shut, however, and not clearly seeing what is really happening to national capital assets. The aim of the Global Footprint Network is to get them to learn to sweat as much about the state of resources as about the state of finances.

While it is natural for humanity to want a good life, using up stocks of resources at a rate greater than that which is actually available as income means building up ecological debt. How can we reduce or pay back that debt? How many planets do we need? These issues raise major philosophical questions. Sustainability, in Wackernagel’s opinion, is basically a matter of collective self-interest, not only of morality.

The overall message to be taken from his address (to around 150 people attending), and the extensive Q&A session following, was that humanity faces the need for transformative change, not palliative incrementalism, and that the EF is a very useful motivating tool in that direction.

Report by John Peet, 22 July, 2008