We have only one Earth. Today, the 7.6bn people on it are using more of its resources than it can provide. Every new person is a new consumer, adding to that demand. There are many steps we must take to make our consumption sustainable - adding fewer new consumers is one of them.
“Anyone who believes in indefinite growth of anything physical on a physically finite planet is either a madman or an economist.”
– Kenneth Boulding, economist
Everyone understands that many of the Earth's resources are finite. We are currently completely reliant on fossil fuels, iron and other metals, minerals and even such basic commodities as sand to keep the modern world ticking over. Adding more consumers makes those resources run out faster.
The Earth also provides for our needs with renewable resources, such as timber, clean water and air, healthy soils and wild fish consumed for food. However, our demands are so great that we are now using those resources at 1.7 times the rate that the Earth can renew them. That rate has increased continually since the 1970s and, unless thing change, we will require three Earths to supply our needs by 2050. (Source: Global Footprint Network)
Some people belive that greater efficiencies in the use of resources mean we will use less of them. There is no evidence to support that, however. A study by the Massachussets Institute of Technology in 2017 evaluated the use of raw materials such as crude oil and silicon, and found that greater efficiencies led to price reductions, making commodities more affordable and, increasing their demand and usage. They investigated more than 60 materials, and found that only in six was consumption decreasing.
The UN's International Resources Panel has projected that resource use per person will be 71 per cent higher than today in 2050.
Food and water
More than 800 million people currently do not get enough food to meet their nutritional needs every day. Meanwhile, 650 million are obese. People go hungry not because there is insufficient food but because our global economic system distributes it unfairly.
However, every extra mouth to feed puts more pressure on our food supply. That is already under threat from multiple factors, including shortage of fresh water, soil depletion, decimated populations of insect pollinators and climate change. The UN currently projects that we will need 70% more food by 2050. In 2015, its Food and Agriculture Organization predicted that at the current rate of soil erosion, the Earth has less than 60 harvests left.
“As the ready supply of healthy and productive land dries up and the population grows, competition is intensifying for land within countries and globally.”
– Monique Barbut, executive secretary of the UN Convention to Combat Desertification, 2017
Water is an absolute basic human necessity, and each person adds to demand Threats to fresh water are even more critical. An MIT study concluded that nearly five billion people will live in water-stressed regions by 2050. The United Nations has calculated that water shortages as a result of climate change could displace hundreds of millions of people by 2030. Regional variations in water availability are extreme but many of the world's poorest regions, and those which have high population growth, are among those with the shortest suppply. Developed countries also suffer from the effects of population pressure on water supply. The densely-populated south-east of England is ranked in the bottom 10% of global regions for ability to supply water to its inhabitants.
As with every environmental problem, while there are many solutions to pollution, adding more people to the population adds more polluters and makes those solutions less effective. While rich countries produce more plastic waste per person, for instance, poor regions where population growth outstrips the infrastructure to dispose of waste may contribute more plastic overall.
Greed, need and injustice
Vast disparities exist in consumption and impact between the rich world and the Global South, and within countries themselves. In order to ensure that there is enough to meet everyone's right to a decent standard of living, the richest must consume more sustainably - in other words, consume less. When nations leave poverty, their fertility rates rates reduce - but hand-in-hand with that increasing prosperity comes increased consumption. People should not have to compete for the Earth's resoures.
That's why population and family size is an issue in both developed and developing countries. Where affluence and consumption is high, reducing the number of new consumers is an effective, permanent way of reducing the drain they place on resources, as well as their environmental impact. It does not mean that people should not do other things to reduce their consumption, but it is an essential, effective method to relieve the pressure.
In the developing world, fewer people means less competition for natural resources, especially local resources such as land and fresh water. In the longer term, fewer people being born means that as countries move out of poverty, their level of consumption will be lower.