Most people I talk to support “sustainability” and “social justice” goals. Ecology teaches us that we need to frame these human aspirations in relation to the biological capacity of the earth: the energy, and resources that support our burgeoning populations and economies.

As human society sets out to achieve ecological sustainability and social justice on earth, we face two serious challenges: One, humanity already over-consumes the biological capacity of the planet; and secondly, humanity suffers from a vast gap between rich and poor.

Free-market fundamentalists claim we’ll close this gap, and restore the planet, by growing our economies, perhaps with “green” jobs, but this business-as-usual approach fails to account for ecological reality.

Do the Math

According to data compiled by the UN, the Global Footprint Network, and Dr. William Rees at the University of British Columbia, total human consumption already exceeds the earth’s capacity by 30 percent. This is known as biological “overshoot.” The UN estimates that most natural services to human societies – forests, fish, fresh water, and clean air – are now declining annually. As human population and consumption grow, our collective overshoot increases.

Meanwhile, the wealthy 15 percent use about 85 percent of the resources – the total energy and materials, the “stuff,” that Earth provides. The “wealthy” includes anyone who has a home, job, transport, access to education, hot showers, convenient fuel, and food every day: people in the so-called “developed” world. If you have those things, you live among the wealthy 15 percent, who use most of the world’s resources.

There is more to social change than the biophysical numbers, but any serious ecologist or justice advocate needs to know how resource overshoot limits our choices to achieve sustainability and social equality. Let’s do the math.

Nature’s rules

Start with these facts:

1. Total human consumption =

     130% of Earth’s capacity

2. The rich 15% use 85% of the stuff;

     while the poor 85% use 15% of the stuff

If we define the sustainable, equitable consumption per person as “1 unit” of stuff, the facts above mean that an average 100 people use 130 “units.” To be sustainable, the total consumption of 100 people needs to be 100 “units” of stuff. And to achieve social justice, each person would use 1 unit. But of course, that’s not how our world works.

Total human consumption of a 100 average people equals 130, not 100, and since the rich 15 use 85% of everything, they use 110 units (130 X 85%). The poor 85, meanwhile, use the other 20 units of stuff.

Therefore:

The average rich person uses:

    110/15   =    7.333  units of stuff

The average poor person uses:

     20/85    =    0.235  units of stuff

How are we doing? Not too well. The average person in the developed nations consume 30-times more than the average working poor, dispossessed, and starving multitudes. And meanwhile, we already use more energy and materials than Earth can annually supply.

So if we want a world of ecological sustainability and social justice, then we must face some difficult facts. To start with, humanity must consume less stuff.

We must reduce the total human consumption for 100 average people from 130 to 100, and then, we must share those 100 units of stuff that the earth can provide.

If we were able to achieve that, then everyone would simply use 1 “unit,” the ecologically sound, socially equitable amount of energy and materials. As we know, in our current situation, we consume more than the earth’s capacity and the rich take almost everything.

Another way to understand this is to imagine humanity as a family of seven people, that earns $100,000 per year but spends $130,000, and one member of the family alone spends $110,000. This family is going broke because one person, 15% of the family, is pigging out.

Dysfunctional? Yes.

Sustainable? No.

Reality bites

By these figures, we see that to achieve sustainability and social justice, the rich would have to consume about 1/7 of what they currently consume. If that happened, the world’s poor could increase their consumption by about 4-times.

That’s the straightforward, biological and physical reality we now face.

Under our current economic system, achieving sustainability and social justice might appear impossible. However, using less and sharing represent nothing more than common decency, the sort of behaviour we supposedly teach our children.

We hear from our alleged leaders, of course, that this is politically and logistically impractical. So, instead, we labour under the delusion that we’ll make the world “equitable” by growing all the economies until the poor, developing countries achieve greater wealth. We’ll make our economies “sustainable” by creating “green” products, hybrid cars, and renewable energy.

If the earth was an infinite storehouse and could provide infinite sinks for our garbage, that would be a reasonable plan. But the earth is not infinite. It remains unequivocally finite.

And Nature doesn’t really care about our social theories, economic presumptions, or our whining about wanting more. Humanity is now like a clever but obsessive adolescent, who must be warned: "Sorry, this will sound really annoying, but there are real limits to your freedom to consume."

Suppose we soften the blow for the rich world, the spoiled child of humanity. We could live within the earth’s capacity if the rich simply cut their consumption in half and the poor could then double their current consumption. Here is how that would work, by the numbers:

The average rich person would use 3.67 units of stuff, instead of 7.33. And then, the average poor person could use 0.53 units of stuff (slightly more than double), instead of 0.235. This equation alone would feed the 1-billion starving, and end world hunger.

Our equation for 100 average people would then look like this:

Rich consumption:  

    15   X   3.67   =   55 units of stuff

Poor consumption:  

    85   X   0.53  =   45 units of stuff  

Total  =  100 units of stuff for 100 average people.

In this scenario we would be sustainable and the world’s poor could grow their economies to the point of doubling their use of energy and resources.

If we achieved this simple change in human consumption patterns, we could exist within the carrying capacity of the Earth.

Is this difficult to imagine? Is it fair? The ratio between the average rich and poor would then be about 7-to-1, far more equitable than the current 30-to-1 ratio. To achieve this, the rich only have to give up half their consumption. That could be achieved primarily by eliminating wastefulness, planned obsolescence, plastic packaging, exotic holidays in jet airplanes, and the most wasteful of all human inventions: cars.

Growth fundamentalists will grumble at this because they imagine a world in which they can look forward to being richer, consuming more, not less. However, biophysical reality sets the limits. We do not get to rewrite the laws of biology and physics for our own convenience.

Two problems remain

Even if humanity could make this simple change – the rich cut consumption by half, the poor double their consumption, and we achieve sustainability – we still face two problems.

First of all, we currently add 75 million new people to the planet every year. What stuff are they going to use?

To live decent lives, these new humans would need the infrastructure services roughly equal to a nation such as France, Germany, or Egypt. And then again, every year.

Human population growth proves to be both an ecological and social justice issue. The planet is finite. I’m mystified that some people find this so difficult to accept. Since we have already reached biological overshoot, human population growth pushes us farther out over the cliff.

For example, we now face declining oil and fish yields, but few people realize that oil and fish yields per capita peaked in the 1970s, thirty years ago. Each day, as we add more people and degrade our ecosystem, the average human – regardless of stock market paper wealth – becomes biophysically poorer.

Like the over-spending family, having a new baby every year, and spending more, while degrading their assets, every year we have less to go around and more mouths to feed.

To achieve sustainability and social justice, we must stabilize human population. We are breaking the back of the natural world with our insistence on endless growth of both population and consumption.

Fortunately, we could stabilize human population with three simple and socially beneficial policies worldwide: Women’s rights, contraception, and education.

The second challenge we face is that we share this planet with millions of other species. These non-human earthlings possess a right to life and habitat as much as we do. Furthermore, humanity relies on the benefits of biological diversity and symbiosis within the ecosystem.

We cannot design human culture to devour every last niche of the planet, every river and forest, the last corner of the ocean and stretch of grassland. We need to preserve every acre of wilderness that still exists on the earth.

Living within Earth’s budget

Growth is not evil, it just isn’t permanent.

In nature, all growth stops. New organisms may replace the old, diversity can increase, but there exist no cases in nature of endless growth. As Dr. Albert Bartlett at the University of Colorado points out, “After maturity, continued growth is either obesity or cancer.” In a finite world, we cannot grow ourselves out of overshoot.

Years ago, Canadian master ecological logger, Merv Wilkinson, came to our small, island community in British Columbia to show us how he had managed to earn a living for over 50 years, selectively logging the forest he grew up in, and still retain a healthy forest with more standing timber than the day he started logging. As we walked through the woods, he explained the nuances of soils, natural seeding, tree growth rates, cutting rates, and selection criteria for harvest. Then, he stopped, thought for a moment, and said: “It’s simple really: Just cut below the annual growth rate.”

That is now the lesson for humanity on a global scale. We simply have to learn to live within the capacity of our single island in space, planet Earth. To achieve this, the wealthy must find peace with a lower-consumption lifestyle.

A reporter from Dubai phoned last week and asked, “Can Dubai become a sustainable city?” and specifically, “could the tourism industry be sustainable?” In age of global warming and declining fossil fuels, the entire airline industry is probably not sustainable. Dubai, of course, is not even remotely sustainable.

Dubai is a city built with oil cash, but the global economic recession brought construction schemes to a sudden halt. Many entrepreneurs fled the city, abandoning some 3,000 cars, found with keys in the ignition and maxed-out credit cards in the glove compartment

Between 2002-2008, the United Arab Emirates (UAE) and partners invested $600 billion in Dubai, creating the world’s tallest building and largest shopping mall, man-made islands, and an indoor ski hill. Dubai has a beach “designed” by Versace, with chilled sand. Meanwhile, sections of the city have no sewage system, so sewage is collected by truck convoys and driven into the desert, where it seeps back through the sand and reappears on the Versace beaches.

On the artificial islands, $20 million villa properties sit empty, without power or sewer systems. Developers will eventually have to protect the faux-island real estate from the rising seas caused by global warming. So, no, Dubai is not sustainable, but neither is any other city.

The sustainable cities are small, modest, usually poor, semi-rural centres, closely linked to local food and energy sources. One of the most ecological western consumer cities is Lingköping, Sweden. In the 1980s, Lingköping’s seven political parties agreed to pursue a non-partisan “Environment Path.” They replaced oil and coal heat with electricity from municipal waste and reduced city CO2 emissions by 40 percent. The city offers free recycling, public transportation that runs on electricity and waste-biogas, bicycle paths, and reduced taxes due to income from the public waste-energy utility.

Even so, Dubai, Lingköping and all cities rely on goods, services, energy, and resources from around the world, delivered by fuel-guzzling transport. We hear a lot these days about “sustainable cities,” but let’s look at the reality.

Cities in history

Hunting and gathering is a sustainable lifestyle. We know this because all animals live this way, and humans lived this way for several million years. Early human fire-making hunters caused local extinctions and disturbed natural habitats, but the real problems with sustainability began with urban concentration.

Four thousand years ago, Sumerian cities on the Euphrates River plains required intensive agriculture and irrigation, causing erosion and salt accumulation. Sumerian texts describe barren soils and “earth turned white.” The communities migrated north along the river seeking new fertile soils, leaving abandoned cities to disappear under the sand.

By 500 B.C., deforestation and soil erosion had left most cities gasping for food and resources. In 460 BC, as the population of Athens swelled with war refugees, filth piled up, and a plague (probably typhus) killed over a third of the population. Cities everywhere began to experience similar plagues, and the human population growth rate began to decline for the first time in history.

Forty thousand years earlier, in Cro-Magnon communities, human population growth remained extremely slow, a few thousandths-of-one-percent each year. But this rate climbed steadily, and by 500 B.C., the growth rate reached 100-times higher, over a tenth of a percent, about 0.13%, per year. However, cities became population drains, and by about 200 A.D., the population rate had dropped below zero, and total human population decreased for the first time in history.

This growth rate did not recover to the 500 B.C. level, for two thousand years, until about 1750 A.D. During those two millennia, cities – centres of filth, disease, toxic smoke, and conflict – killed off more people than they produced. Lewis Mumford explains in The City in History that small, rural Medieval towns remained relatively clean and functional, but between 1200 and 1500 A.D., large cities became centres of death, and human population dropped incessantly. Meanwhile, burgeoning empires required ever more resources from distant lands.

The forests of Europe had been devastated by 1550, which provoked the use of coal fuel and an industrial boom in Europe. Burning coal increased urban air pollution, causing more death and disease. In 1661, John Evelyn described sections of London as “suburbs of Hell.”

Smoke inhalation, typhus and cholera killed urban citizens everywhere. In the twentieth century, with the additional toxic effect of leaded gasoline exhaust, thousands perished from “killer fog” in London, and U.S. cities, including Pittsburgh, Chicago, and St. Louis. Four thousand died in London in December 1952 and hundreds died in Los Angeles in 1954. But modern industrial empires, like their ancient predecessors, still sought more resources from greater distances.

The biophysical city

Dr. William Rees at the University of British Columbia, who developed the “ecological footprint” analysis, points out that most cities require the environmental services from a land base 300 to 1000-times the city area. Rees points out that a city is a “biophysical entity” that includes the complex of land, water, atmosphere, resources, and waste sinks required to support the human population.

Rich consumer cities of Europe and North America require the most ecological space, but all modern cities carry an ecological debt to nature. I live in Vancouver, Canada, which prides itself as being a fairly “green” city with bike paths and urban gardens, but even so, Vancouver requires a global biophysical area about 390-times the city itself.

In the study, Ecosytem Appropriation by Cities," published by the Royal Swedish Academy of Sciences, Carl Folke and colleagues estimate that the 29 largest Baltic cities – including Copenhagen, Stockholm, Oslo, and Helsinki – appropriate for their resource consumption and waste an area of forest, agricultural, marine, and wetland ecosystems over 560-times the area of the cities themselves. New York requires a total eco-footprint almost 1000-times the city’s geographic area. Tokyo requires twice the entire domestic biocapacity of Japan.

The Folke study shows that the 744 largest cities worldwide require more CO2 sequestration than the entire world’s forests could provide. “If the goal,” write the authors, “is sustainable human settlements, the increasingly limited capacity of ecosystems to sustain urban areas has to be explicitly accounted for in city planning and development.”

Meanwhile, human activity continues to degrade the ecosystems that keep cities alive. Each year, we loose about 13 million hectares of forests and 6 million hectares of arable land, while adding some 75 million new humans – the combined populations of Mexico City, Mumbai, Seoul, and Sao Paulo.

“These data show that, in material terms, ‘sustainable city’ is an oxymoron,” says Rees. “Modern cities are entropic black holes sweeping up the productivity of a vastly larger and increasingly global resource hinterland and spewing an equivalent quantity of waste back into it."

Reduce consumption

Dubai may be one of the more obvious examples of reckless urban consumption, but it is not alone. Most Modern cities remain vulnerable to distant food supplies, degraded cropland, declining fossil fuel resources, and climate change impact, including rising seas and human migrations.

“To act consistently with our best science may well require a planned economic contraction,” says Rees. He believes the wealthy nations “should plan to reduce their ecological footprints by almost 80 percent” to consume only an equitable share of global biocapacity.

Peter Victor, in the book Managing without Growth, believes this is possible, that human society can dump its untenable economic ideas about growing consumption. The only way out of our dilemma – ecosystem “overshoot” – is to consume less stuff. There is no magic technology that will allow us to continue consuming at current rates, much less a growing rates. But Victor, Rees, and others believe we can live higher quality lives with less consumption, particularly if we turn urban density into an advantage.

Here are some things we need to do to make cities less destructive and more sustainable. Many modest, small rural communities already do these things, which is why they are already more sustainable:

·        Reduce per capita demand for land and water resources (consume less stuff).

·        Reduce fossil energy consumption, and all energy consumption.

·        Preserve farmland and grow local food for local consumption.

·        Share: create co-housing, public transport, and food cooperatives.

·        Be satisfied with second hand clothes and furniture, and make simplicity, modesty, justice, and ecology your fashion statement.

·        Improve urban infrastructure, water, sewage systems, and recycling.

·        Gain efficiencies with neighbourhood scale technologies, such as heat pumps, electricity co-generation, district heating/cooling, using industrial waste heat systems.

·        Create low throughput and closed loop industries, in which waste energy is captured and waste materials become feedstocks for other uses.

·        Eliminate planned obsolescence in product design; build things that last.

We have to rethink cities as complete ecosystems that fully account for their consumption. “The aggregate effect,” says Rees, “would be global sustainability.”