How Many Earths Does It Take To Support An American Lifestyle?

It is no secret that the world’s seven billion-plus people vary wildly in their consumption habits: the subsistence farmer in sub-Saharan Africa uses far fewer resources to support his or her lifestyle than a wealthy financier living in Manhattan. Disparities also exist within nations, as well as between countries of similar socioeconomic status (for example, the average middle-class Japanese uses less space and energy than the average middle-class American).

In 2012, science writer Tim De Chant produced an infographic illustrating the amount of land that would be required if the entire world lived like the populations of nine selected countries. This includes not just living space, but land needed to cultivate food crops, support livestock, grow cotton for clothing, and so on. Needless to say, the results are interesting, as they show quite vividly just how differently people throughout the world live.

The BBC, my source for this infographic, provides details regarding the methodology and conclusion of this research:

De Chant was using a subset of data produced by the Global Footprint Network (GFN), which has been attempting the tricky business of measuring the impact of humans on the planet since 2003.

“Ecological footprinting” is where researchers look at how much land, sea and other natural resources are used to produce what people consume – how many potatoes they eat, how much milk they drink, the cotton that goes into the shirts they wear and so on.

They do this by using published statistics on consumption and the amount of land or sea used to produce the quantity of goods consumed.

“It’s a book-keeping approach for resources,” says GFN director and co-founder Mathis Wackernagel.

The key questions for GFN, he says, are: “If there is one planet – how much planet is available per person and how much planet do we use per person.”

The answers are expressed in an unusual unit – the global hectare, defined as a biologically productive hectare with world-average bioproductivity.

The average American, says GFN, uses seven global hectares, compared to a global average of 2.7, according to the most recent GFN figures (based on data from 2011). It’s this figure of seven global hectares that allows Wackernagel and his colleagues to calculate that it would take four Earths – .or to be precise, 3.9 Earths -. to sustain a population of seven billion at American levels of consumption.

However, the U.S. does not consume the most on this measure. It is in fact ranked fifth among countries with a population of one million or more. Kuwait comes top with 8.9 global hectares (5.1 Earths), followed by Australia (4.8 Earths), the United Arab Emirates (4.7 Earths) and Qatar (4.0 Earths). The others in the top 10 are Canada, Sweden, Bahrain, Trinidad and Tobago, and Singapore.

Granted, unlike the other countries in the top ten, the U.S. is very populous — with around 320 million people — and it is projected to grow to over 400 million by 2050; that translates to a lot more more Earths being consumed. Moreover, Australia, the Gulf States, and to a lesser degree Canada are also slated for fairly rapid population growth in that timeframe. Combined with the rapid economic growth of big countries like China and India — which between them will add hundreds of millions of people to the large consumption pool — this means a lot of pressure on an already strained planet.

One curious thing to note is that according to the Global Footprint Network, the world’s population is currently using not one, but one-and-a-half Earths.

That’s because it takes account of carbon emissions. The forests and oceans of the world absorb a lot of carbon dioxide, but we are currently emitting more than the planet can handle — and Wackernagel’s team has calculated how much extra land and sea we would need to absorb it. They estimate that we need an extra half a planet.

If we now look again at the average American footprint — two-thirds of that is made up of carbon emissions.

This means that for the four Earths we would need if everyone consumed like an American, more than two-and-a-half of those would be needed just to absorb carbon dioxide.

How much more growth can our planet handle? Recall that the issue is not so much one of raw population growth as it is of per capita consumption; if most of the world consumed as comparatively little as wealthy Japan or the Netherlands, such growth would not be as troubling. As it is, the most populous countries in the world, on average, have far lower consumptions rates than more developed countries. If the middle and upper classes of the world began drawing down the many resources they use — the amount of food that is eaten and wasted, especially meat, or the amount of fuel that is burned — we could likely accommodate the growth in population and income levels.

Culture and economics play a big role in all this; not everyone with the money to consume a lot necessarily needs to. But a complex intersection of market pressures (like ubiquitous advertising) and conspicuous consumption (buying things to communicate status or conform to new trends) makes it difficult to resist. Societies with an abundance of living space — incidentally most of the ones among the top ten of the GFN — underestimate how little space there is worldwide to support their consumption habits. There might even be an evolutionary predisposition to consuming as much as one can when possible, a holdover from when our species spent most of its existence in scarcity.

Long story short, there are many powerful psychological, sociological, economic, and cultural forces at play that will make addressing this problem difficult. Necessity is already helping to change things a bit: younger Americans, like many youths elsewhere in the world, are not buying as many homes, cars, and other big purchases as they used to, mostly because they simply cannot afford it. Will human beings be able to resist the temptations to consume more, or will it take shortages in income and/or resources to force that upon us? Will we be able to change our profit-driven economies to be less dependent on consumption and instead more focused on maintaining a steady-state of growth, based on need rather than pushing more and more unnecessary purchases?

We only have so much Earth left to decide, though to be fair there are caveats to at least this study’s conclusions:

“It seems a little odd to convert what’s happening in the atmosphere into a proxy measure and pretend you’re measuring land when you’re not,” says Fred Pearce, environment correspondent for New Scientist magazine.

But Mathis Wackernagel says it is important to include carbon emissions in the calculation to capture the “total package” of our activity.

Another criticism — made, for example by Linus Blomqvist, Director of Conservation at the Breakthrough Institute in California — is that there is insufficient data from many parts of the world to create meaningful ecological footprint estimates. Researchers just don’t know how sustainable some agricultural practices are, and therefore to what extent resources are being overused.

“Our critique is that these figures don’t say anything about sustainability of cropland, such as the erosion of soil,” Blomqvist says.

Wackernagel accepts this criticism, to an extent.

“I would be perfectly blunt – our numbers are certainly wrong. I’m convinced our numbers are underestimates.

“There are aspects on which no good data exists that we don’t include, so our demand on nature is larger.”

While these figures may not be perfect, Wackernagel says that governments can find them useful as a way of thinking about policies on the environment.

For example, Switzerland publishes ecological footprint estimates on its Federal Statistics Office website. The U.K., meanwhile, has formed a Natural Capital Committee to study how the country consumes its natural resources and how long, at current rates, they will last.

Whatever the specifics, it is certainly the case that everything from fresh water to arable land to fossil fuels is finite; finding new or alternative sources, or replenishing current stocks, requires a lot of public and political will, to say nothing of the costs. We need to start investing more in improving and preserving the global commons, in conjunction with altering eating, living, and transportation habits. What are your thoughts?

Hat tip to Predrag for first sharing this article.

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