The population of Earth is 7.3 billion right now and is expected to reach 10 billion by 2100. This has led to concerns about whether our planet has enough resources to sustain this huge number of people. Land, water, energy and food are the most basic requirements of every human. Even now, the distribution of these four important needs is skewed, with some people having everything and others barely surviving. How would overpopulation affect this already disproportionate distribution of essential basic needs of human beings? How can Earth sustain us and for how long – let’s find out:
How long can Earth sustain us
Overpopulation, strain on food production, dwindling energy and water resources as well as climate change and nature will play a role in the survival of the human species. Let’s take a detailed look at each of these factors:
Growing population is an undeniable fact. Better infant mortality as well as growing population of old people has added to the numbers. There have been efforts by governments to curb population growth by increasing awareness about the birth control methods, which has led to the decline in population growth, especially in developed countries, where women are more literate.
According to the UN, the number of babies per woman has declined from 4.7 in 1970 to 2.6 in 2010. But, it will still take many years for significant reduction in population growth. In a study conducted in 2014, it was found that even if 2 billion people were dead suddenly, and even if every government in the world adopted the controversial one-child policy, there would still be around 11 billion people on Earth by 2100. So is the carrying capacity of the Earth enough to support so many people?
How many people can Earth Support
Many experts are unwilling to predict any future scenario, because there is no precedent to it, and the Earth has never seen such massive population before. Therefore it is hard to tell how many people our planet can support. The number would depend on the amount as well as technologies of food production, electricity, transport etc. There would be more migration to urban centers in middle and low income countries, which researchers say, might have a less impact globally on the planet’s resources. This is because, historically, the trend of consumption is quite low in urban centers of middle and low income countries. So even if a few billion people move to cities and towns, the distribution of resources would not be affected.
The rich consume more
An expert suggests that it is not the population but the scale as well as nature of consumption which is the main culprit. In poorer countries, people consume much less of everything – food, water, energy and land and produce much less waste. Whereas, in richer, developed countries, consumption per capita is much higher, and they also produce more waste as well as emissions.
According to many studies, wealthy countries’ consumption is out of proportion with their populations. The comparison here that experts make is, living off our savings bank account as if it was our steady income! The Worldwatch Institute calculated that every person on Earth requires 1.9 hectares of land, for food, clothing and energy production, and also to absorb waste. An average American consumes 9.7 hectares, which suggests that exhaustion of resources is imminent is the entire world population were to follow the American trend of consumption. At that rate, the Earth can support only 1.5 billion people by 2100.
In order to calculate can Earth sustain us, there has to be balanced distribution of resources and people have to control their greed, in order for others to benefit. For example, excess food and energy which is produced in developed nations could be donated or sold at a cheaper price to poorer nations.
Treating water and land resources respectfully and frugally
Human beings have, in the span of a century, managed to over utilize and pollute natural resources to an unimaginable extent. Aquifers are dwindling, fertile soil, fisheries and forests have been overused. Human created global warming has led to ice caps melting and oceans being polluted beyond belief. It is alarming to think of how can Earth sustain us if we continue using resources at this rate.
Water is the elixir of life. Biologically, an adult need 1 gallon or less of water daily. In the US, in 2010, the water use was 355 billion gallons freshwater which came to 1,000 gallons or 4,000 liters on an average per person every day. Half of that amount was used for electricity, 1/3rd for irrigation, and the rest for household use.
The WHO estimates that 2.1 billion people already do not have access to clean drinking water. $4.5 billion lack water for sanitation, which is true for both developing and industrialized countries as the water is contaminated with pollutants like insecticide and fertilizer runoff, fracking effluent and heavy metals. To have clean water resources, humans have to reduce consumption as well as take measures to reduce water pollution and if we do not want exhaustion of resources such as clean water.
Population data indicates that the doubling time of population has increased. In 1800, population was 1 billion, with doubling time of 300 years. In 1927, 2 billion population mark was reached with doubling time 127 years, 4 billion in 1974 indicated doubling time of 47 years. In 2023, the population would reach 8 billion with doubling time 49 years, and by 2100, the population would be leveled off to 10-12 billion.
The leveling off suggests that our planet has already reached the tipping point of the number of people our planet can support. Scientists suggest that this leveling off will be due to the planet’s carrying capacity – the amount of population at which deaths due to disease and starvation balances birth rate. Still, 10-12 billion population is a staggering figure and we still cannot predict can Earth sustain us.
Another factor which will influence population growth is climate change. 20 million people are already food insecure and climate change will add to the problem. To support the extra billions by 2100, the lifestyle of the affluent of high income countries has to tone down as an example to low income countries. This would help the entire planet to manage resources in a sustainable manner and perhaps support the huge population in 2100. Reducing emissions and controlling pollution has to be treated as an imperative need rather than a ‘cleaning up’ measure if we have to survive for long on Earth.