Australia

Australia's population was estimated to be 26.6 million in 2023. Over the past 20 years, the population has grown by 35 percent, significantly higher than the OECD average of 13 percent and faster than other young, developed nations like Canada (27 percent) and New Zealand (30 percent). While Australia enjoys a vast land area of 7.7 million square kilometers with a population density of only 3.5 people per square kilometer (Profile of Australia's population, 2023), there are cumulative costs. Population pressures have increased demand for housing, particularly for the younger generation, while supply has failed to keep up. Younger Australians, especially those aged 25 to 34, now have a lower homeownership rate compared to previous generations at the same age, particularly in capital cities. This growing disparity, worsened by slow productivity growth and rising fiscal pressures, puts the intergenerational bargain at risk, threatening the well-being and economic prospects of future generations. With housing becoming increasingly unaffordable, younger Australians face more challenges in securing stable homes, further deepening the divide between them and older generations (Hutchens, 2025).

Additionally, overpopulation in Australia is damaging the ecosystem, as evidenced by a steady environmental decline over the past 100 years. As the population grows, urban expansion increases the risk of bushfires, flooding, and the loss of agricultural land. It also leads to deforestation and the destruction of native plant and animal habitats. The demand for water in urban areas exacerbates the situation, with energy-hungry desalination processes used to supply water during dry periods. This ongoing environmental damage makes it harder to regenerate ecosystems and sustain natural resources (Sustainable Population Australia, 2024).

South Korea

In South Korea, overpopulation is a significant concern, especially in major cities like Seoul. As of 2025, Seoul's metropolitan area population is approximately 21 million, with a population density of about 1,376  people per mi square.(South Korea Population Live,2025) This high density has led to issues such as housing shortages, increased living costs, and environmental degradation. A 2024 study highlighted that younger generations are particularly affected, facing challenges like high real estate prices and job competition. (Yookyung L, Seungwoo H. 2024)

Additionally, South Korea’s growing population has led to serious overcrowding in cities, making daily life more difficult. The high number of people in urban areas has caused traffic congestion, packed public transportation, and limited living space. (Seoul Solution,2024). Many residents struggle to afford housing, and competition for jobs has increased. As more people move to cities like Seoul, the stress of overcrowding continues to rise.  These issues highlight the need for better urban planning and policies to manage South Korea’s growing population.

Singapore

In Singapore, the level of overpopulation has impacted urban life, particularly in housing and transportation. At the end of 2024, Singapore’s population was 6.04 million (Vanessa L, 2024). Singapore has a limited land area which makes housing expensive, as high demand from an increasing population pushes prices up. A report explains that with a growing population and only a small amount of space available, property prices continue to rise, making it difficult for many residents to afford homes. (Abram L, 2025)

Additionally, Singapore’s dense population has led to increased demand for public infrastructure. The high number of people in urban areas has resulted in packed trains, frequent traffic congestion, and rising competition for space. Many commuters experience longer travel times due to overcrowded transport systems. While the government has introduced measures to improve urban mobility, such as expanding MRT lines and promoting car-lite policies, the challenge of balancing population growth with infrastructure development still remains.

New Zealand

In New Zealand, the level of overpopulation is lower than in many other countries, but urban areas like Auckland still face challenges due to population growth. As of the end of 2024, New Zealand’s population was around 5.2 million (Worldmeter, 2025), with Auckland being the most densely populated city at 1.7 million residents. In addition, New Zealand's population density is 52 people per mi square which is much lower compared to other countries.  The main challenges include increased demand for infrastructure, housing, and services, along with potential strain on resources and the environment. A report states that more than 100,000 households in New Zealand are classified as crowded, highlighting the ongoing housing issues in urban areas. (Stats NZ, 2024)

Nigeria

In Nigeria, overpopulation is a major issue. As of 2025, Nigeria’s population is over 230 million, making it the most populous country in Africa. Nigeria is also predicted to overtake the US to become the world’s third most populated country by 2051. In addition, Nigeria’s rapid growth is caused by their younger population coming into child-bearing age, with currently half of the population under the age of 19. (Population Matters, 2024)

As a result, Nigeria faces issues such as inadequate living conditions, lack of healthcare  and more. For example, in Nigeria's most overpopulated city, Lagos residents often live in informal settlements, squatter housing and unauthorised land developments. Residents of Lagos are deprived of essential basic facilities and are faced with poor living conditions such as the lack of drinking water, poor health care access, poor structural and quality of housing. (Olaoluwa P.A , 2018)