In his recent documentary A Life on Our Planet, David Attenborough reveals his vision of the world’s future. His recollection of his career parallels the story of the Earth: once dominated by nature, now 'run by humankind for humankind'.
Rapid growth of the human species has thrown off the balances of nature, the effects of which we can see in the progression of climate change and increasing natural disasters. Attenborough highlights the key forces of this imbalance: the growing population of the human species and our unsustainable way of living.
The question is, however, whether overpopulation is really the greatest threat to our planet, or whether it is more complicated than that.
The problem of a growing population, explained
Overpopulation is the idea of the human population exceeding the amount of its environment’s ‘ecological niche’. In other words, it is a state where the planet can no longer support the number of people and their consumption of natural resources. It is therefore associated with the depletion of non-renewable resources.
As a result, through the process of excessive consumption and proliferation of technology, scientists stress that the impact of human activity on the environment has pushed the Earth into a geological epoch known as the Anthropocene.
With roughly 83 million people being added to the world's population every year, The UN 2017 Revision of World Population Prospects report estimates there will be around 9.8 billion people in 2050 and 11.2 billion in 2100. The effects of which include a decline in fertility rate, resulting in not only a slower rate of population growth but also an older population.
The issue of an ageing population is one that is often discussed with overpopulation. Globally, the number of persons aged 80 or over is projected to have increased to 909 million by 2100, nearly seven times its value in 2017. This will have a profound effect on societies, increasing demands for stronger fiscal and political measures on healthcare, pension planning and social services. Although disparities remain across the globe, life expectancy has also generally increased, especially in Africa.
Overpopulation and theory
The issue of overpopulation is often associated with the Malthusian growth model.
Thomas Malthus believed in an eventual crisis point where ‘arithmetic’ economic production cannot meet ‘geometric’ population growth, resulting in overpopulation. He described ‘positive’ and ‘preventative’ checks which would increase death rates (such as war, disease, famine) or decrease birth rates, for the idea of the greater good. While this can be seen as a problematic view, this line of reason is the basis of certain policies around the world such as the case of sterilisation of men in India.
An opposing line of thought is one of cornucopian nature. This is the idea that the continued progress in technology will provide the answers for provision of materials for the human population. An example of this is the Green Revolution and the innovation of chemical fertilisers.
The danger of overpopulation: Earth's capacity
Population growth puts an increasing pressure on the planet’s limited resources, and subsequently, on the environment. The Earth's exact 'carrying capacity' is still undecided, but it is still considered to be inevitable given our current trajectory.
An increase in people means an increase in carbon footprint, as well as an increase in the consumption of limited resources. The core concern of overpopulation is having too many people for the amount of these natural resources. This is also known as ecological overshoot: turning resources into waste at a faster rate than the planet can supply them. Fossil fuels are a good example of this, as they take millions of years to form, but are consumed at a much more rapid rate.
But is overpopulation really the only threat?
In his documentary, Attenborough discusses how in the coming years, the human species will reach its maximum population, 'at a rather higher level than the Earth can really accommodate'. After which point, 'everything will become easier', meaning the fight for a more sustainable way of living becomes more achievable, since the variable of population growth becomes ‘stabilised’.
While the world population is increasing, it is increasing at a slower rate, and will eventually stabilise at around 11 billion in 2100. But even if the population no longer increases, our excess consumption of natural resources and waste production will continue to grow, while our non-renewable energy sources will not. So, a sole focus on numbers ignores the other factors which also drive environmental degradation: inequality in access to resources and conspicuous consumption. These factors play a significant role in climate change and will continue to increase, even when world population peaks.
Consumption and global inequality
The issue of having limited resources for a growing population is also an issue of distribution. David Pimental (1999) writes about how the finite nature of Earth's resources controls human numbers, with examples such as malnutrition, poverty and pollution-related diseases. While that may be the case, it is also inherently linked to the (lack of) distribution of goods and resources.
Dependency Theory describes a world system which is dependent on resources flowing from ‘periphery states’ (states that are considered underdeveloped or developing) to core and wealthier states, at the expense of the former. The issue of climate change further enhances the North-South divide, as countries of the Global South have the lowest greenhouse gas emissions yet remain the most vulnerable to climate change disasters.
It becomes evident that the issue of inequality is fundamentally linked to issues of climate change, waste and overpopulation.
Our tendency to consume excessively both facilitates global warming and is rooted in our consumer culture. Fast fashion is an example of where harm to the environment through our consumption becomes evident. For example, it takes 2,700 litres of water to produce the cotton for one single T-Shirt. A consumer culture which is based on 52 seasons instead of 2-4 inevitably results in mass waste. A study by LABFRESH found that the UK produces 206.456 tonnes of textile waste in a year.
The impact of this consumer culture is felt worldwide and also facilitates global inequality. Garment factories in developing countries have to work exhaustively to maintain the rate of consumption which is not only dominated by the Western standards of living, but often fosters exploitative and dangerous working conditions.
So, what can be done?
There is a responsibility on every individual and institution to help battle climate change.
Governments must keep engaging with global projections to help the environment, such as the Paris Climate Accord (read our Cheat Sheet here), and ensure their policies are in accordance with the international aim. Education and technology are other areas in which advancement and awareness come hand in hand. A World Bank report underlines the effect of educating women in developing countries, in order to decrease the number of children she is likely to bear.
Progress can be made on micro-level as well. Attenborough underlines the importance of a plant-based diet, highlighting the increase in land yield and decrease in pollution if more people were to do so.
Fighting threats: our only option
Overpopulation has obvious implications on the strain of the world’s natural resources. But stabilisation of population alone will not slow the rate of climate change. Our exponential rate of consumption and subsequent global inequality are two intertwined factors which will continue to threaten the planet, post population peak.
They are key drivers of climate change. To fight against inequality, climate change and environmental degradation is a fight against excessive consumption. It is a difficult challenge in world that Attenborough accurately describes, ‘that demands more everyday', but nevertheless it ‘is once again our only option’.
For more resources on these issues, head to our Climate Crisis section.