The phrase “Carrying Capacity” was coined by the 18th-century Philosopher, demographer, and economist Thomas Malthus. In his words, the world had a maximum number of people it would support sustainably based on existing resources.
Malthus foresaw a period when the population would overstretch existing resources, and there would be mass starvation to death. Across the 18th Century, there was an exponential growth of the population. On the other hand, growth in food production was linear. That meant, at some point, there would be more people than existing food. The modern world has outlived Malthus’ theory that was entirely based on food, majorly produced using agrarian techniques.
Presently, the question to most demographers is the number of people the world can support sustainably. Most scientists agree that the world has the capacity to support 10 billion people, and it is estimated the world is 2.2 billion from that mark. It is expected that we will hit that mark around around 2045, 25 years from now. Table 1 indicates that at the high population growth rate, by 2050, the world will have 10.8 billion, or 800 million above what many scientists consider it the world’s optimal population.
Graph 1: Population Projection 2010-2100
One question that is not adequately answered by scientists is the extent to which the world (or resources) should support a person?. At the very basic level, human beings need food (a resource whose scarcity Malthus argued would lead to mass starvation), shelter, clothing, freshwater, and clean air.
In the 18th Century, when Malthus was studying demographies, much of the existing needs that are considered essential today were either non-existent or had not gained priority among every person. These needs include education, health care, transportation, property, and employment. Anyone would, therefore, argue that at an optimal level, existing resources should be able to not just afford people the basic needs but also the resources that are seen as essential in the modern world. After that, the big question is whether the world has sufficient resources to afford every existing individual those essential needs and if the same resources, even while increasing, would be able to support a higher population than we have now. I look at some of the essential services and resources necessary to provide them.
Fresh Water and Food
Malthus’s main focus was food, but modern changes to human life have limited access to safe drinking water, making it one of the limited resources now. Millions of urban inhabitants 100 years ago had access to clean water in nearby water sources. Today almost all open water sources around urban centers are polluted due to human activities. This is not just essential for drinking, cooking, and sanitation, and it is also essential for food production. Considering the rate at which water is being polluted, the world needs a balance at which the existing freshwater will be sufficient for the existing population. One would argue that water is an unlimited resource, that should be provided, but why isn’t it despite its overabundance.
Technology has made it possible to produce food in large quantities, but with the consumption rate and issues that exist along the supply chain, the world is still not able to provide food for 800 million people around the world. That already is an indication that the world is running at a level beyond it has the ability to feed. If it has no capacity to send food to around 12 percent of the population, what guarantees exist that it will send food when the population doubles? Equally, as the world races to meet global food production, questionable technologies are on the rise. The increase in GMO food production is inspired by a potential acute shortage of food. It seems that at some point people may trade their health for food, which may undermine our existence in this world.
Manufacturing Goods for Global Population
If there is any positive side of Covid-19, then it is nature’s opportunity to relax from excess human activities. In March, NASA images showed a dramatic decline in pollution levels in China as industries shut down due to the virus. Manufacturing goods for the current population has resulted in massive environmental pollution. High air pollution in China is now a major health concern, with close to half a million lives lost prematurely.
The cost of providing health services to address respiratory issues resulting from breathing polluted air continues to stretch resources in the country. The level of pollution across the world continue to cause serious concerns. Most manufactured goods – ranging from cars, electronics, to textiles and apparel – serve around half of the global population. That means manufacturing goods for 3.4 billion persons is causing damage that is threatening human life. Anyone would wonder what environmental damage will be caused if the economic status of the other half improved, such that the world would not be forced to manufacture things for them. With population increase, the world is facing another environmental catastrophe in trying to meet the demand for more people.
The immediate effect of the world’s effort to meet demands for the ever-growing population is the environmental population. The dangers of climate change are vast, but one sector that is likely to be hit hard is the production of food. Over the past century alone, the world has lost millions of arable hectares to desertification. That is land that has been supporting rural communities. These are people who have no knowledge of what is causing the skies to dry. They only experience their land becoming unproductive, acid rains, and experience the death of their animals. The end result is a famine that calls for government interventions, another nightmare around the world. Climate change will affect food production significantly and stands out as a danger to subsistence communities.
Efficiency and Logistical Challenges
Half of the global pollution live in rural areas, and almost all of the farm their own food. The majority of these 3.4 billion people are subsistent farmers, and a few are commercial farmers. These people produce enough food for everyone, but most have no mechanism to send food to everyone.
That explains why some 10 million people still succumb annually to starvation. As these populations face the increasing danger of having unproductive land and losing their animals due to climate change, they will have to rely on food produced in different regions. The current governments around the world are unable to deliver these foods and save 10 million lives. The desertification of half of the rural land that has been supporting rural communities will mean the world has almost two billion people to supply food from other regions. Even at the very best, most governments will never reach the efficiency level to supply food to these communities. It is also worth noting that the world, due to issues beyond human help, will never achieve 100% efficiency in the food supply chain.
Currently, around 25% of the food produced goes into waste. Reducing that wasteful even with modern technology will remain indefinitely elusive. The point is that people who argue governments will do more obviously overrate governments. The government’s ability, subject to existing concerns like limited infrastructure development, inadequacy of real time knowledge, insecurity and other challenges will hamper its level of efficiency. In other words, the number of people that governments would support when necessary has a limit, contrary to popular belief that governments can provide basics to everyone if it wants.
Environmental Conservation and Global Threat
Thirty-one percent of the global land is forest, a natural habitat for billions of other animals and living organisms. But increased demand for trees to meet human needs like furniture, paper, and others, and increasing demand for space to build houses and factories, and increase demand for arable land to support increasing human population has put so much strain in the forest land. These have led to massive deforestation. In regions like Kenya, the urge for infrastructure development has seen some land annexed from parks to construct roads, high rise buildings, railways etc. These are habitats for millions of equally important living organisms, and it is that level of encroachment that is now threatening human life. Increasing demand for food is the reason people are consuming wild animals, and everyone now knows the risks of doing that. If human beings were not consuming wild animals, diseases like Ebola, and now Covid-19 would be unheard of. Animals host tens of thousands of viruses and other diseases which human have no knowledge of, and passing these diseases to human can be catastrophic. Scientists claim that pushing animals out of their natural habitat affects how they live, and this would result in new diseases as they try to adapt. If the human population continues to increase, displacing animals from their habitat, and converting them to food, will continue. The risks would continue to pose a threat to human sustainability.
The main policy paradox is whether the world should continue accelerating its efforts to provide people with modern needs like employment, healthcare, education, and others, while at the same time threaten agricultural production to billions of people, whose ability to supply food will remain another riddle. Should the world continue to put more pressure on land inhabited by other animals, risking diseases like Covid-19 that have proved elusive to our existing resources?
With manufacturing to create employment and things that support modern needs like medical services, education, and transportation, people will lose access to clean and safe water. Communities located in regions that have a high concentration of industries already experience challenges accessing clean and safe water. A rational verdict is that the world is already beyond the population level; it can comfortably support without endangering the existence of human beings. That calls for active policies to put a pose on population growth rates.
Graph 2: Low v High Income Countries Population Growth Rate
Graph 2 would possibly point where proactive measures to curtail the increase in population is necessary. There are 47 Low-income countries according to United Nations, including 33 in Africa, 9 in Asia, and 4 in Oceania, and one in Latin America. High-Income countries comprise Europe, Northern America, Australia, New Zealand, and Japan. The low-income countries have 730 million persons in 2020, but the high birth rate will push that to 3.5 billion in 2100. On the other hand, high-income countries will move from 1.3 billion in 2020 to 1.9 billion by 2100. It should not go unnoticed that the economic status of low economic countries will not grow at the pace of the population growth, risking a further strain on existing limited resources. It would irk anyone to see low income countries marked for depopulation policies, but they need it more than any country that has achieved some replacement level growth.
The bigger question is to think if the world will be able to support twice the current population, which will hit 16 billion by 2100 on the high variant level, and somewhere around 12 billion if human depopulation interventions are initiated.