HOW MANY PEOPLE CAN THE EARTH SUPPORT? (2)

Posted on February 1, 2015 by Bert Hielema

February 1 2015

HOW MANY PEOPLE CAN THE EARTH SUPPORT? (2)

We know that nowadays the earth is quite small. When I emigrated to Canada in 1951, it took the M.S. Veendam 10 days to sail from Rotterdam to New York. Today an airplane covers that same distance in a couple of hours, thanks to special high octane fuel. Going back 150-200 years ago sailing vessels were years on the way from one continent, Europe to another, Australia. Then the world population was only a fraction of what it is now, while their ecological footprint was negligible. And yet even 1600 years ago when Rome collapsed, as Thomas Homer-Dixon relays in his The Upside of Down, the real causes of the Fall of Rome were: “the rising complexity of all parts of Roman society – including its bureaucracy, military forces, cities, economy, and laws – as the empire tried to maintain itself……..It needed more and more energy, and eventually it couldn’t find enough.”

Sounds very much like something that could happen today as well even though today there is a surplus of the energy stuff, a sign that the world economy is in tatters. What is striking now is the speed of events, creating Black Swans, unexpected developments, faster than ever. Total dependency on oil and electricity also means total collapse when they fail to deliver.

The story of Thomas Malthus is well-known. Two hundred years ago, this Presbyterian minister said population would race ahead of food supply. In an essay published in 1798, the English clergyman argued that human numbers always increase more rapidly than food supplies and that humans are condemned always to breed to the point of misery and the edge of starvation. The two centuries since his famous essay have not been kind to Malthus’s theory. During that time human numbers have increased from fewer than one billion to today’s 7+ billion. In many parts of the world, food production has grown faster than the population, thanks to the opening of new lands, mechanization, fertilizers, pesticides, better water control, improved breeds of plants and animals, and better farmer know-how. It’s the oil we eat! Though many of today’s bottom billion people live in misery on the edge of starvation, Malthus would be amazed at the relative well-being of most of a vastly enlarged population.
That Malthus’s theory failed widely during the past two centuries does not prove that it will remain wrong for the future. That there are many more billions today does not guarantee future increases.

The early Christian writer Tertullian said (around AD 200, in De Anima): “We are burdensome to the world, the resources are scarcely adequate for us… Truly, pestilence and hunger and war and flood must be considered as a remedy for nations, like a pruning of the human race becoming excessive in numbers.”

That was when the population of the whole planet was maybe 100 million or so. We reached the first billion mark by about 1850. By 1928, it was about 2 billion. In my lifetime it has more than tripled. It passed seven billion in 2014. Note that: humans took 150,000 years to get to the first billion. The most recent billion arrived in just 12 years.

Nobody knows how many people the planet could hold. The UN has predicted that fertility would decline and longevity would increase until the global population stabilized at nine billion in 2300. I sincerely believe that we will never reach the figure of nine billion. There are a number of factors at work that will limit expansion: (1) As people become more affluent, they have less children. Already Russia is losing population, and so is Japan. (2) Arable land is disappearing at a fast clip, and what is there is increasingly contaminated. (3) Water is the great limiting factor. It takes 1000 tons of water to grow 1 single ton of wheat. (4) Climate Change will also reduce yields, as too much rain in some areas and drought elsewhere, will make agriculture a more hazardous occupation.

I believe that we are now already close to capacity. When the financial system collapses the industrial world too will cease to be. To develop the needy energy sources and renew the electrical infrastructure will take trillions of dollars which will not be available once the debt-laden economy gives up the ghost. When that happens a massive die-off will occur reducing the world’s population to a fraction of what it is now.

Still people have been busy to calculate the incalculable. Joel Cohen, the Rockefeller University population biologist, argues in a 1995 book How Many People can the Earth Support?  that it isn’t a question like “How old are you?” which only has one answer at any one time. Cohen argues that you could fit one billion people each a meter apart, into a field 64km square. So everybody in the world would fit easily into a city the size of Toronto or Chicago. But that has nothing to do with supporting these people, feeding them, providing sanitation, keeping them alive. That is the real question, because human action has its own “ecological footprint”; there has to be so much land to provide food, clothing, shelter, medicines, building material, fresh air and clean water for any one human. It takes, according to some calculations, 2.1 hectares – about 5 acres – of land and water to provide for one average human. The important word is: average. The American footprint is about 10 hectares or 25 acres. So if all humans lived at US standards, we’d need another five Earths.

How Many People Can The Earth Really Support?

The number depends on nature and on human choices. By providing numbers, population projections help nations shape social and economic policies. Before too long, Cohen notes, people are likely to confront difficult trade-offs between population size, economic well-being, environmental quality and cultural values. The clear message of the projections is that people cannot forever continue to have, on average, more children than are required to replace themselves,” Cohen says. “This statement is not an ideological slogan. It is a hard fact. For example, conventional agriculture cannot grow enough food for untold billions of people–not enough water falls from the skies. The finiteness of the Earth guarantees that a ceiling on human numbers exists.”

During the last 50 years, estimates of the number of people Earth can support have ranged from fewer than 1 billion to more than 1 trillion. The estimates vary so wildly, Cohen says, because they use different methods and make different assumptions about how people will be willing to live in the future.

In 1992, the United Nations projected that if 1990 growth rates continued, the world would have about 21.2 billion people in 2050. However, if the worldwide average fell to 2.5 children, Earth’s population would grow to 12.5 billion in 2050. If the average rate slowed to 1.7 children, the population would increase to 7.8 billion.

Here is what Cole concluded: “Every demographer knows that we cannot continue a positive rate of increase indefinitely. The inexorable arithmetic of compound interest leads us to absurd conditions within a calculable period of time. Logically we must, and in fact we will, have a rate of growth very close to zero in the long run.”The World Hunger Program at Brown University estimates that, with present levels of food production and an equal distribution of food, the world could sustain either 5.5 billion vegetarians, 3.7 billion people who get 15 percent of their calories from animal products (as in much of South America), or 2.8 billion people who derive 25 percent of their calories from animal products, as we in the wealthiest countries, do.

 

Still no answer to my original question.

Fact is that we live in a world with finite resources. Actually the sudden drop in oil prices will speed up oil depletion, because measures to limit its use will be largely abandoned, while efforts to explore the far-out sources such as the Arctic and hydrological fracturing will stop because exploiting them will be a losing proposition. Also those currently in the oil-fracking business will go bankrupt, making it difficult to pick up the pieces later. No wonder some analysts now expect $200 barrel oil in the not too distant future. Is that the tactic that motivated Saudi Arabia to flood the market with oil?

Then there is land. When God created the world the entire globe was like a gigantic garden and immense forest. Julius Caesar in his De Bello Gallico relates that the Roman Legions marched through forests on the way to Germania for weeks on end. Woods and lush vegetation represented the condition of the entire globe. Human exploitation, animal overgrazing caused the flourishing lands to become deserts. That’s why in the Bible –Isaiah 32: 15 – it says that the desert will become fertile field again. Now most of the Middle East is desert land, good for nothing, and so are its people. People become like the land they inhabit. The more land becomes desert, the more people lose their bearings.

I found the following in the Harper’s article The Oil We Eat.

“Plato wrote of his country’s farmlands some 2500 years ago:

“What now remains of the formerly rich land is like the skeleton of a sick man. …Formerly, many of the mountains were arable. The plains that were full of rich soil are now marshes. Hills that were once covered with forests and produced abundant pasture now produce only food for bees. Once the land was enriched by yearly rains, which were not lost as they are now by flowing from the bare land into the sea. The soil was deep, it absorbed and kept the water in loamy soil, and the water that soaked into the hills fed springs and running streams everywhere. Now the abandoned shrines at spots where formerly there were springs attest that our description of the land is true.

“Plato’s lament is rooted in wheat agriculture, which depleted his country’s soil and subsequently caused the series of declines that pushed centers of civilization to Rome, Turkey, and Western Europe. By the fifth century, though, wheat’s strategy of depleting and moving on ran up against the Atlantic Ocean. Fenced-in wheat agriculture is like rice agriculture. It balances its equations with famine. In the millennium between 500 and 1500, Britain suffered a major “corrective” famine about every ten years; there were seventy-five in France during the same period. The incidence, however, dropped sharply when colonization brought an influx of new food to Europe.

“The new lands had an even greater effect on the colonists themselves. Thomas Jefferson, after enduring a lecture on the rustic nature by his hosts at a dinner party in Paris, pointed out that all of the Americans present were a good head taller than all of the French. Indeed, colonists in all of the neo-Europeans enjoyed greater stature and longevity, as well as a lower infant-mortality rate–all indicators of the better nutrition afforded by the onetime spend down of the accumulated capital of virgin soil.

“The precolonial famines of Europe raised the question: What would happen when the planet’s supply of arable land ran out? We have a clear answer. In about 1960 expansion hit its limits and the supply of unfarmed, arable lands came to an end. There was nothing left to plow.”

What happened since 1965 or so was grain yields tripled thanks to the so-called Green Revolution. Plant breeders tinkered with the architecture of wheat, rice and soya so that they could be hyper-charged with irrigation water and chemical fertilizers, especially nitrogen. With the possible exception of the domestication of wheat, the green revolution is the worst thing that has ever happened to the planet. All this is now back-firing because of lack of water, scarce capital and overuse of chemicals.

How many people can the earth support?

Conclusion next week.

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