Introduction

You have heard something about it – the perspective of Thomas Maltus that food supply and population growth are correlated, and that restriction of food supply naturally checks population growth. But you probably know something about the Green Revolution, too - a series of research, development, and technology transfer initiatives, occurring between 1943 and the late 1970s that increased industrialized agriculture production in many developing nations.

So how are population growth and environment resources linked? What will happen when population reaches 9 billion or more in 2050? And, is it only about food? You are about to find out.

From Malthus to Environmental Footprints

In 1798 Thomas Malthus had a very simple idea – that agriculture and transportation in its 18th-century version could only support a limited number of people, and that any population growth above this level will be checked by famine, disease and conflict. Malthus was right. What he didn’t know, however, was that the Industrial Revolution was about to begin, and there was a good reason for calling it a revolution. It changed everything – and transportation in particular. Now large bulks of food (particularly grains) could be transferred easily around the world. Industrialization also improved the productivity of agriculture, for example by providing cheaper and more efficient tools.

Then came the Green Revolution, propelled in the 1950s by the findings of Norman Borlaug and other agronomists. By using certain crop varieties, irrigation and fertilizers it was now possible to achieve much higher production rates. The growing world population could be fed, though some developing countries in sub-Saharan Africa still experienced periodic famines.

So it looked like things were really getting better. Little by little, however, Western societies started to find out more about the impact of economic growth on the environment. The 1970s and the 1980s witnessed the increasing influence of environmentalists on the policy discourse.

But it was in the 1990s when William Rees and Mathis Wackernagel introduced the concept of ecological footprints. They wanted to measure how the human appropriation of the earth's resources relates to its carrying capacity. They said that if the planet is “full” of people who are depleting its natural capital, making more stuff cannot make people better off. In result, addressing equity through economic expansion becomes a physically impossible strategy that only accentuates the conflict over resources. That is why they proposed the “ecological footprint” methodology, which provides a natural capital account that can determine at each scale, from the global down to the household, how much of nature’s services are appropriated for supporting these entities.

Their methodology is now used by the Global Footprint Network to measure how much land and water area a human population requires to produce the resource it consumes and to absorb its wastes, using prevailing technology. Its findings show that it now takes the Earth one year and five months to regenerate what we use in a year. We are maintaining this overshoot by liquidating the Earth’s resources. There are, of course, objections to this approach. I find it particularly interesting that some criticize the absence of options to fully offset one’s environmental impacts reduces the credibility of the indices and renders them a doom-saying, off-putting instrument for individuals and policy-makers. In other words, it makes us feel bad about ourselves.

But how does the population growth dynamic correlate with this environmental overshoot? A simple linear trend of population growth would point to an increase of the ecological footprint. Well, it’s not that simple. As we saw earlier in the Population Series, the bulk of population growth now happens in the developing countries. Using the ecological footprint data we can see that a teenager in the US has twice as much footprint as a teen in France, and four times the footprint of a Somali teenager. So population growth by itself is not sufficient to explain the environmental overshoot. However, developing countries grow not only in numbers, but in economy size, too. This is evident in the ecological footprint of China, which increased sharply after 2000 – obviously due to the economic expansion.

So a safe conclusion can be that both population growth and economic growth lead to greater ecological footprint that cannot be satisfied by the existing biological capacity. Some say that it's overconsumption, not population growth that is the fundamental problem. And this problem is exacerbated by mineral resources depletion.

Depleting Resources or the Peak of Everything

The current economic development is unprecedented. Never before has the humankind mastered its own environment with such reach and intensity. There are many reasons for this economic boom pattern – from education and culture to capital intensity. But sometimes a major contributor is forgotten – and that is energy. In fact energy use and output are tightly coupled with energy availability, playing a key role in enabling growth.

The world economy today relies to a great extent on a certain group of finite fossil fuels – the hydrocarbons. One of those fuels – oil, is the major energy source for transportation, allowing the massive commerce among nations and territories. The problem is that oil production is probably peaking at the moment, and will diminish in 20 years, while oil demand will soar, driven by both economic growth and population dynamics. So the peak oil phenomenon will most certainly challenge the current recipe for economic growth. But it does not end there.

There are many different mineral resources – such as bauxite, copper, iron ore, magnesium, phosphate rock, potash, rare earth metals, etc., which are already experiencing their peak production rate. In the future it will be harder and more expensive to get hold of such resources. High raw materials prices will drive down economic growth. Developing countries will suffer in particular, since their economies are less resource-efficient and alternative energy technologies cost more. They also specialize in producing low-value, bulkier products that may simply become uncompetitive if the transportation costs skyrocket.

We also deplete bioresources. Ocean fish stocks – an important source of protein for many of the developing world poor, are also diminishing. We now have sound data that shows the profound reorganization of seabed ecosystems since the nineteenth century industrialization of fishing. Deforestation is a growing concern - more than 80 percent of the Earth’s natural forests already have been destroyed. As you can see on the chart below, agriculture is the main reason for tropical deforestation.

Good Ol’ Pollution

Apart from resources depletion, the current unsustainable economic growth model affects the environment by polluting it. But let’s not talk about pandas here – let’s focus on the human beings. As you can see from the map, countries in Asia and China in particular are strongly affected by air pollution, leading to illness and death. There are other forms of pollution – such as water pollution, soil pollution, and even heat pollution.

I’m not even scratching the surface of the climate change debate and its impact on developing countries. You can find many useful information sources on the Th!nk 2 Climate Change homepage.

The Bottom Line

The bottom line is that the current pattern of economic growth is environmentally unsustainable, even without taking into account population growth. If we add population growth to that, we’ll see that the Earth simply cannot provide enough resources for all of us in the long term. True, recent production peaks for various mineral resources will probably restrict growth and will ease to some extent the pressure on the environment. But even at relatively low growth projections, the world’s poor will find themselves in a new poverty trap, defined by resource overexploitation and scarcity. This picture of uneven, unsustainable growth can lead to a really dark scenario for the future, which will be reviewed in the last section of the Population Series.