Sustainability in an overpopulated world

World population has experienced exponential growth in recent history, presenting both opportunities and challenges for sustainability. This relentless growth has raised concerns about our ability to control our climate and provide essential infrastructure and resources, such as energy, water and food.

Human population growth took thousands of years to reach one billion around 1804. The second billion was added in just over a century, around 1927, and the third billion took even less time, occurring in 1959. The pace of growth continued to accumulate, with the population exceeding eight billion in 2023. This remarkable increase in population has been fuelled by several factors, such as increased life expectancy due to improved healthcare and income, need for warriors and manpower, failure to control birthrate due to lack of access to contraceptives, dominant cultural and religious beliefs, socio-economic factors, such as the belief that more children is a form of social security, lack of comprehensive sex education, desire for sons, misinformation and myths, gender inequality and political barriers.

As the population continues to rise, so does the demand for drinking water. Many regions already face water scarcity, and this problem is likely to worsen with increasing population and climate change. Therefore, implementing water-saving technologies, reducing water loss from main pipes, developing and redirecting agriculture towards plants that need less water, enhancing desalination technology, rainwater catchment and better management of water resources can all help alleviate water scarcity issues.

Feeding a growing population is a monumental challenge too. Agricultural techniques are often unsustainable, due to excessive use of fertilisers and pesticides, leading to soil degradation and reduced biodiversity. Embracing sustainable farming practices, such as organic farming, crop rotation and agroforestry, can help increase food production while minimising environmental degradation. In regions like Sub-Saharan Africa, traditional farming systems often involve crop rotation and intercropping. Organic coffee farming in Ethiopia has been managed by avoiding synthetic chemicals, using organic compost. In Sikkim State, India, the transition to organic farming has improved soil health, reduced water pollution and preserved biodiversity.

Meeting the energy needs of a larger population is another concern, as our current dependence on fossil fuels for energy production has significant environmental impacts and contributes greatly to climate change. Renewable energy can tackle this impediment in the future, but a transitional time is needed. Transitioning to renewable energy sources like solar, wind, hydrogen and hydroelectric power can reduce our dependence on fossil fuels and mitigate climate change.

For a sustainable future, studies show that when women have access to education and family planning, birth rates tend to decline. Bangladesh is often cited as a compelling example of how education and family planning programmes can lead to a significant decline in birth rates. Bangladesh experienced a significant decline in birth rates over the past few decades. In the early 1970s, the total fertility rate (TFR) was around 6.0, meaning that, on average, a woman would have six children in her lifetime. By 2020, the TFR had dropped to approximately 2.1, which is close to the replacement level, where a population replaces itself. Lower birth rates allowed families to invest more in health, education, and overall well-being of their children. This also contributed to increased opportunities for women to participate in the labor force and earn ahigher income.

Policymaking is an important solution to overpopulation. China has a well-documented history of population control measures, particularly its one-child policy implemented in 1979. The one-child policy, initially introduced to address population growth and resource constraints, had a significant impact on China's demographic landscape and has been both praised and criticized. In 2015, it was officially replaced with a two-child policy due to several implications, such as labour shortage in some regions and challenges associated with supporting an aging population. 

In 1972, Singapore introduced the "stop at two" policy, which encouraged couples to have no more than two children. The policy aimed to slow population growth and improve living standards by offering incentives for couples, such as priority in public housing allocation and free access to childcare services. Disincentives included financial penalties for additional children, such as cancelling free education and healthcare, as well as enforcing restrictions on housing benefits.

Is there a negative birth rate? Japan, Italy, Germany, Spain and Greece, for example, have negative birth rates. Justifying this outcome includes an aging population, economic- cultural strains, lack of family support, work-family life imbalance, prioritising career to family, high unemployment, limited job security and changing societal values. One wonders: Is there an optimum rate of birth?

Many factors influence the answer, such as economic growth, health conditions of mothers and their socio-economic conditions, however, many experts suggest that an ideal birth rate is one that maintains a population at replacement level fertility. This means that, on average, each woman has enough children to replace herself and her partner in the next generation. Replacement level fertility is typically around 2.1 children per woman in developed countries, accounting for some children who may not survive to adulthood or may not have children of their own. 

In many underdeveloped countries, higher birth rates are common due to factors like limited access to contraception, lower levels of education, and cultural norms that encourage larger families. High birth rates can have both positive and negative implications depending on the country's situation, particularly its economic growth. In some cases, higher birth rates can support economic growth, especially in countries with a young and expanding labor force. It can also serve as a form of social security in societies with limited access to pension systems, as more children can provide support for aging parents. On the other hand, very high birth rates in the absence of corresponding improvements in growth, healthcare, and education can strain resources and services, leading to issues such as poverty, and malnutrition.

Efforts to achieve sustainable population growth in underdeveloped countries often involve empowering women with education, economic opportunities, healthcare and family planning. Spacing between births policies can lead to a reduction in a country's total fertility rate, contributing to a healthier mother and child. Short birth intervals can increase the risk of maternal and child health problems, such as low birth weight and maternal anemia. Slower population growth can have positive environmental implications by reducing the strain on natural resources and limiting carbon emissions. 

In conclusion, sustainability facing an ever-increasing world population is undeniably challenging. By addressing issues related to population growth and resource management, we can work towards a more sustainable future. Education, family planning, sustainable agriculture, renewable energy, water conservation, and responsible incentives are just a few of the tools at our disposal. However, it will require international cooperation, innovation, and a collective commitment to prioritise sustainability to overcome the challenges presented by our growing global population.