Ecological Footprint is a term that has been making the rounds lately. Let’s take a look at exactly what it means.
Ecological Footprint is an analytical methodology that is used to measure the amount of global resources a population (or and individual, activity, country, and so on) uses. In a recent post, One Scary Chart, I wrote about explosive and exponential population growth observed in the last few hundred years. Well, Ecological Footprint is a great tool for measuring the impact of our new found population on resources and compare that demand to available resources.
What is Ecological Footprint
Footprintnetwork.org defines Ecological Footprint as:
A measure of how much area of biologically productive land and water an individual, population or activity requires to produce all the resources it consumes and to absorb the waste it generates, using prevailing technology and resource management practices.
This methodology started life around 1992 when the first academic publication about the issue was created by William Rees. The concept and methodology was the subject of the PhD of a student of Rees, Mathis Wackernagel. Since then the methodology has developed into a sophisticated tool and is routinely applied to the patterns of production and consumption of over 200 countries.
While the calculation method is complex and
involved, at the highest level, Ecological Footprint seeks simply to compare Consumption Footprint to Biological Capacity.
A Few Key Definitions
For a few of definitions (again from footprintnetwork.org):
Embodies all the resources, including energy, necessary to provide it to the consumer. In full life-cycle accounting, everything used along the production chain is taken into account, including any losses along the way.
The capacity of ecosystems to produce useful biological materials and to absorb waste materials generated by humans, using current management schemes and extraction technologies. (Also called biocapacity.)
The [land or water] area used to support a defined population’s consumption.
These concepts are brought together to create the Ecological Footprint that is most often reported in global acres (an average of the capacity of actual acres since every acre varies in capacity due to factors like soil quality, climate, water availability, management practices and so on) or in terms of the number of earths required to meet the demand.
Biocapacity calculations are based on 5 different area (land or water) types:
Our Current Footprint
So where are we today? By most calculations we are consuming presently around 1.5 earths of capacity. This means that capacity is being depleted faster than it renews. For this to make more sense we can think of extractive resources such as oil to see that we may be extracting oil at a rate faster than it replenishes, or that we are producing carbon dioxide faster than it can be absorbed.
In fact, while many consumption footprint elements are growing, none are growing nearly as fast as demand for carbon dioxide absorption. The following image shows some recent trends.
As you can see from the chart, starting around the mid 1970’s, demand is believed to have been outstripping supply leading to net liquidation of resources with carbon dioxide leading the charge.
Who are the Worst Offenders?
Let’s take a look at Ecological Footprint by region and at the figures for the US based on 2010 data tables from footprintnetwork.org (Raw data and some of the calculations are downloadable here: The 2010 Data Tables).
(Note that the values calculated in units of earths is based on the global average biocapacity of 1.8 hectacres per person) To understand the earths figure a bit better, if all people on earth consumed at the rate of 4.49 earths per capital as is the case in the US, we would need 4.49 earths-worth of capacity to stay even. We can clearly see that production (biocapacity) is higher is some areas than others – but also that in all areas, demand is overshooting capacity with the global consumption equal to about 1.51 times what we are presently producing. (It is important to not confuse production with extraction – for example, in the case of oil, accessible oil is being extracted at a high relative rate, but not being produced (or replenished in other words) at a high relative rate.
Now keeping in mind the vast majority of present and coming future population living below the standards of more developed regions, what is to be done about this situation. That of course is the most important question facing this and near term future generations!
Elasticity vs. Tradeoffs
We can imagine in certain areas that there is elasticity in supply – for example through better science and management, we can surely increase food production. In other areas we can likewise see inelasticity – for example in production of new oil reserves. We can also see severe tradeoffs between areas. Oil may be burned to run desalination plants, but this produces more CO2. We can of course clear more forests to create arable land – but this likewise reduces carbon absorption capacity.
Intuitively it seems a pipe dream that all people on earth could (at least in any near-term scenario) experience the consumption rates of those in more developed regions.
On a modestly more optimistic note, there certainly are things that can be done to reduce consumption – especially by those of us in regions consuming the most.
On the energy front, at least we know that there is more than enough renewable energy to go around and that it is just a matter of willpower and cost (at least near term cost) to harvest it.
CEO | Rain8 Group LLC