How many earths would it take for everyone to live like an American? That’s the question answered by the Ecological Footprint, a method of measurement coined in 1990 by Mathis Wackernagel and William Rees of the University of British Columbia. Ecological Footprint accounting essentially pits the productivity of natural capital against the consumption of human beings. It measures how much biologically productive land and marine area (as the source of natural resources) we would need to sustain a group of people. So, how many global hectares– that’s the normed unit of measurement– does it take?
Let’s look more into how the Ecological Footprint is calculated: on the demand side, we account not only for the materials consumed, but also for the capital necessary to manage waste products. The waste management is especially significant because it includes carbon emissions. We measure the Footprint in terms of global hectares (gha), which is just a hectare of land with world average bioproductivity. Looking at supply, the land’s biocapacity measures its productivity and ability to remove that waste. The aggregate of available land multiplied by its yield and equivalence factors equals the biocapacity. Yield factor assigns a relationship between local and global productivity, while the equivalence factor is assigned based on what function the land serves. The categories of productive surface area include cropland, grazing land, fishing grounds, built-up land, and forest area (which doubles as a resource provider and carbon sink).
We often use the Ecological Footprint (demand) in conjunction with regional biocapacity (supply) to determine whether an area would be able to sustain itself. If demand exceeds supply, we run an ecological deficit; in the opposite case, we have an ecological reserve. On the global scale, when we use more than what can be produced, we enter a state known as “overshoot.” (Note that a region can run a deficit but not be in overshoot, provided that it imports what it needs instead of just overusing resources within the specific boundary. Globally, however, deficit equals overshoot.) This means that the natural capital is being depleted, and its regenerative ability compromised. A significant issue with overshoot is that current consumption jeopardizes future production. So it starts a type of cycle of further overtaxing the land. (Imagine that you overfish an area. After some years, there will be less fish in total. Fewer parents means fewer offspring, so there’s lower annual yield. Even if you instate a complete moratorium on fishing, there are less fish available to reproduce and repopulate the waters, so it will still take longer to go back to the original state.)
Overshoot is so important to measure because environmental issues disproportionately impact people in poorer countries. The people who lead the most ecologically expensive lives tend to be in wealthy, industrialized countries. We contribute the most to climate change, but we are the least affected by any ensuing environmental disaster. This disparity explains in part why overuse continues. It’s also difficult to delineate the ecological limits; most of the time, depletion is time-delayed. And psychologically, it’s hard to imagine that we could ever use all the water in the Ogallala or kill all the passenger pigeons in the world.
Why is it that industrialized nations have such a large footprint? Or, many people will ask, can we afford to let developing countries reach our level? If they fully develop, will they also contribute more to the footprint? That question highlights the worst of human hypocrisy. What right do rich nations have to tell those countries what they can or can’t do? Are we any more deserving of a higher standard of living than everyone else? The moral implications of any such claims are damning, yet the fact remains that the earth does have a carrying capacity. In a study, Daniel Moran cross-referenced countries’ United Nations Human Development Index (a measurement of how developed a country is, with emphasis on quality of life) with their Ecological Footprint.
His data suggests positive correlation between development and sustainability. His ratio of national Footprint per capita to global biocapacity per capita provides a snapshot of a country’s sustainability. It’s a direct comparison of an individual’s usage to an equitably allocated share of available resources. (It’s also known as the earth-equivalents ratio, as it can be used to answer that hallmark question.) Critics of his work claim that this analysis lacks scalability, and uses arbitrary boundaries. These are not unfounded worries, as the Footprint varies extensively even within a nation. Certainly, the global measurement presents the most striking reality of human sustainability. However, the complex governance structures across these boundaries lend a certain pragmatism to considering countries as unique entities.
Significantly, the least developed countries receive the greatest increase in HDI/gha– the diminishing returns of development mean that it’s our most logical choice to allocate increases in EF to less developed countries. If we imposed a limit on our Footprint values, they should be allowed the largest increases, because they derive the most benefit. Admittedly, the HDI has an upper bound influencing this trend, and spending of the wealthier countries improves quality of life in ways the HDI is not calibrated to measure. But the developed countries trend away from sustainability as they reach some developmental threshold. This data needs to be looked at in the context of foreign policy. The Senate’s historic disdain for environmental conventions follows “America First” type thinking, but from an objective standpoint, other countries have a greater need to consume. (So don’t ridicule Paris for giving China and India some leeway.)
Moran defines a country as sustainably developed if it falls into HDI>.8 and Ratio<1.0. Notice in the dataset that most nations with a sustainable ratio have too low of a development rating. The goal, then, is to move into the constraints — that’s the minimum to be called sustainable development (on the graph, the area inside the shaded gray box). At the time this was published, only one nation met the criteria. Lower-income countries should try and maximize development gains for environmental cost, while developed countries like the US need to reduce our consumption. Conservation’s two fronts must both be fought. At home, we have so much to improve. But the Footprint also speaks to a shared global responsibility for what happens here on earth. In order to protect the environment, we have to protect our fellow man, and to work to ensure a better future for everyone. The only logical course forward is to oversee better development. We need to make sure that growth is done right. You cannot say that it is a solution to just condemn people to poverty. Development is inevitable and necessary, and Moran’s study certainly should not be used to say that some countries shouldn’t develop. It’s quite the paradoxical opposite: in order to find a sustainable future, we need to improve the development process (yes, that does mean increasing the Footprint by aiding developing countries). Consider that some people in these countries fight daily just to survive. Sustainability really won’t be on their minds. But if they get to a position where the immediate future is secure, then that’s where we start talking about the long term. Only after fully realizing this potential can we begin discussion about transitioning to a wholly sustainable world.
In our Ecological Footprint, carbon emissions sequestration is the largest land type. It’s not the direct resources needed for goods that costs us, but the energy to produce them and power our lifestyles. This is perhaps the most disputed aspect of the Footprint, as some people believe carbon is too heavily weighted. In recent years, the marine sequestration factor has been reduced in calculations, which makes land demands even greater. Considering what we have seen in Chasing Coral and our understanding of the impacts of global warming, what are benefits to making net-zero emissions the baseline? Note that America has one of the highest rates in the world of CO2 emissions per capita– more than China and India combined.
The Ecological Footprint has so many implications for development, but it’s difficult to know how to use information. What is the relationship between fair and sustainable? Considering that the three factors in aggregate Footprint demand are per capita consumption, resource intensity in production, and population size, a Malthusian projection is justified. But what’s the best way to reduce population growth? How much of demand is cultural? (Is conspicuous consumption and luxurious excess built into our very economic system?) To what degree can technology serve as a staircase for human growth, and what is our role in working with developing countries? As engineers, it’s our duty to understand science in a holistic context. The footprint tells us that things need to change. Technology alone can’t carry us. We need to work for a future of global cooperation and the right kind of development. ———
If you’re interested in measuring your personal ecological footprint, check out this calculator! How many earths would it take if everyone lived like you? How do you compare to the average? What are ways you can reduce your consumption?
Just for fun, check out Hans Rosling’s bubble time-lapse data! I didn’t reference it in this blog but 10/10 would recommend playing around with it. There’s a ton of variables to plot against each other.
What do you think are flaws in the Ecological Footprint measurement? Check out this source that criticizes the application of EF to development. (He’s very cynical and mocks the “How many earths…” question. Which I view as an understandable way of presenting information to the world at large. But overall, presents some good arguments.)
That article ^ is actually a response to this one \/. Which is also the Moran study.
For the math and methodology:
Quality overview of EF and some of its limitations.
A beautiful look at carbon sequestration.