Population and consumption in a changing world

The people of the Johns Hopkins University are not exactly average, and I imagine that most of them do in fact understand the exponential curve. However, understanding the mathematics is not the same as understanding its implications in the real world.

The most striking example of an exponential curve is that of the human population: In 1800 the total global population was one billion people, in 1900 it was 1.6 billion, in 2000 it was 6.1 billion, and now, only 15 years later, it is almost 7.4 billion. A report by the Royal Society projects that the total global population will reach between eight and 11 billion by 2050.

These numbers are staggering, even worrisome. How long until there is no more space to fit everyone? Fortunately it is very unlikely that humans will ever run out of space, but unfortunately, according to current trends, humans will run out of resources to support that growing population.

So the real question should be: How long until there are no more resources to provide for everyone? The answer depends on two factors, which will be the topic of this EcoSeeker article, namely, population and consumption. The amount of resources society uses is equal to population times consumption, which is basically the amount of people multiplied by the amount they each use. Society relies on these resources for survival, but the environment can only provide so much, and while technology and innovation are may influence this equation, there is a limit.

The agricultural and industrial revolutions drastically increased the ability to utilize natural resources, and things like renewable energy and genetically modified crops will continue that trend, but humans cannot rely solely on technology.

If the population does reach the widely accepted estimate of nine billion people by 2050, providing food, water, shelter and medical care to everyone will be nearly impossible, especially as climate change complicates the matter. The math will not continue to add up indefinitely, so in order to create a sustainable society, humankind must seriously consider population and consumption.

The demographic transition model explains how the population and consumption of a society develop over time. According to the model, in the first stage a harsh natural environment causes a high death rate, but the birth rate is also high, so the overall population remains constant.

During the second stage, improvements in agriculture and medicine lower death rates while birthrates remain high, so the population grows rapidly. In the third stage, as the economy grows and societal factors such as education and gender equality improve, birth rates decrease and population growth slows until in the fourth stage when birth and death rates are both low and population remains stable.

A possible fifth stage would have birth rates fall below death rates, causing a decrease in population.

This model correlates well with the data and although different areas experience various stages of development at different times, the general trend is clear. Up until the 18th century, population growth rate remained relatively constant. Then it rose rapidly until the middle of the 20th century and peaked at about two percent per year. At the beginning of the 21st century, the growth rate slowed to 1.2 percent and is projected in a report by the Royal Society to hit 0.5 percent by the middle of the century.

This is good news. However, the other half of the equation is consumption and although development decreases population growth, it actually increases the rate of consumption. Even accounting for the change in population growth, global energy use has risen drastically. In 1800 the global energy use per capita was 20 gigajoules (GJ), in 1900 it was 25 GJ, and in 1950 it was 40 GJ. Then in 2000, in was up to 62 GJ.

As a society develops and its people’s basic needs are met, consumption rises because luxury items become commonplace and the demand for material goods rises. This consumption requires more energy, water and raw materials and is therefore just as influential as a high population.

This is not to say that development is bad since development means there is a strong economy and infrastructure system, food and water, healthcare and education, equality and an overall higher standard of living for the people. These are all great things, but they require resources, and even though population growth is trending downward, the product of population and consumption certainly is not. The key is to find a balance.

In order to create balance between population and consumption, developing areas with high population growth need to stabilize their populations by educating women and creating easy access to family planning services. Areas which are already developed also need to radically decrease their consumption.

While many might fear that lowering consumption means stagnation and even deterioration, that doesn’t have to be the case. The key is to figure out how to develop and thrive in a sustainable way so society can stabilize population and lower consumption without affecting productivity.

This is not a simple task because in order to create the necessary political, economic, scientific, technological and cultural changes, there will need to be a fundamental shift in thinking about what it means to be successful, considering quality rather than quantity. Also, even though technology and innovation may not be able to discount the math behind the exponential curve, they will be essential to enabling these changes.

Although figuring out how to develop sustainably is a huge part of creating a sustainable society, doing so will be, like any other progress, composed of countless small actions. As an individual you don’t have much control over global population, aside from advocating for women’s rights in developing nations or making the very personal decision to have fewer children, but you do have control over your own consumption.

The best way to measure this is by looking at your ecological footprint, which quantifies the amount of resources your lifestyle requires. It is impossible to improve without knowing where you started, so I suggest calculating your footprint on one of the many websites available. Answering the questions should give you a sense of what factors have the largest influence and, while some of them you can’t really change, there are others you can. Focus on what you can change, and challenge yourself to change the exponential curve.