In 2025, the total population of South Korea is projected to be around ***** million. In thirty years, the number of people aged 15 to 64 is estimated to decrease by one-third, while the number of older adults is anticipated to more than double. Additionally, the overall population is expected to decline by around *** million people by that time. Declining birth rate Several factors are contributing to the expected demographic changes in South Korea. Firstly, the birth rate has been declining for years. As of 2024, South Korea had the lowest fertility rate in the world. This trend continues despite the efforts of successive governments to encourage young people to have children. An increasing number of South Korean women are prioritizing their careers, often choosing to focus on work rather than starting a family at a young age. While the employment rate for South Korean women is still lower than that of men, it has steadily risen over the past decade. Increase in life expectancy Secondly, life expectancy in South Korea has steadily increased due to improved living standards and healthcare. The average life expectancy at birth for South Koreans has risen from less than 75 years to almost 83 years over the past twenty years. As a result, the proportion of people aged 65 and older has grown from less than ** percent to around ** percent in the last decade.

In 2025, South Korea's male population is projected to reach about ***** million, while the female population is estimated at ***** million. In the long term, South Korea's population is expected to decline, reaching about ***** million in 2072.

In 2024, the birth rate in South Korea stood at 0.75 births per woman. The country has long struggled with a declining birth rate, dropping below one birth per woman in 2018.

South Korea: Population ages 0-14, percent of total: The latest value from 2024 is 10.57 percent, a decline from 10.97 percent in 2023. In comparison, the world average is 25.79 percent, based on data from 196 countries. Historically, the average for South Korea from 1960 to 2024 is 26.83 percent. The minimum value, 10.57 percent, was reached in 2024 while the maximum of 43.45 percent was recorded in 1966.

In 2024, the number of births in South Korea stood at *******, a slight increase compared to the previous year. Around two decades earlier, this number was twice as high. Declining fertility in South Korea A phenomenon that most East Asian countries and territories grapple with is a stark decline in fertility rates. This is especially evident in South Korea, which has the lowest fertility rate in the world, far below the 2.1 children per woman threshold that represents replacement fertility. In response to the expected economic consequences of a declining population, South Korea has implemented various initiatives to encourage married couples to have children. Factors contributing to low birth rates in South Korea One major element is the societal change in attitudes toward childbirth. In a survey, half of the South Korean respondents asserted that marriages can be happy without children, and a sizable share also stated that having children was dependent on economic factors. In addition, an increasing number of South Koreans are choosing not to get married. In 2023, South Korea recorded one of the lowest numbers of marriages in its history. Furthermore, there has been a growing trend among South Korean women to prioritize their financial independence and career continuity over traditional expectations of childbearing.

Graph and download economic data for Infra-Annual Labor Statistics: Working-Age Population Total: From 15 to 64 Years for Korea (LFWA64TTKRM647N) from Jun 1999 to Sep 2025 about working-age, 15 to 64 years, Korea, and population.

In 1900, the fertility rate in the region of present-day South Korea was six children per woman, meaning that the average woman born in South Korea in that year could expect to have six children over the course of their reproductive years. This number began to fluctuate in the 1930s, when the Japanese administration (the Korean peninsula had been annexed by Japan in 1910) promoted fertility as part of the war effort, before fertility dropped below 5.2 births per woman in the aftermath of the war. It then increased above 6.3 in the 1950s due to the devastation and mass-displacement caused by the Korean War. As stability returned to the region, South Korea's fertility rate would fall sharply throughout the remainder of the century, as modernization, urbanization, and the implementation of family planning programs would see fertility fall to just over 1.5 children per woman by 1990.

Sex-selective abortion and gender ratios Abortion was illegal in South Korea between 1953 and 2020, although it was permitted in some cases from 1973 onward. Despite this, these laws were rarely enforced, and sex-selective abortion became widespread following advancements in ultrasound technology. In many Asian societies, it was often preferred to have male children as they were viewed as being better long-term providers for their parents and they would carry on the family name. In South Korea in the early 1990s, the practice of sex-selective abortion became so widespread that the gender ratio at birth was 114 males for every 100 females (reportedly as high as 125 in some cities), compared to the historical and natural average of approximately 105 males per 100 females. The government then prohibited doctors from revealing the gender of unborn babies to the parents in 1987, and introduced more severe penalties in 1994, in an attempt to revert this trend. The gender imbalance then reduced in the following decades, and has been at 106 males per 100 females since the 2010s (roughly the natural average). Abortion rights in South Korea were expanded in 2021.

Lowest in the world? Despite government initiatives aimed at increasing fertility, including financial incentives, South Korea's fertility rate has continued to fall in recent years, and today is at around half of replacement level. In 2020, it is estimated that the average woman born in South Korea will have just over one child over the course of their reproductive years. Some critics cite economic factors, such as high education and housing costs, for the reason that young couples are postponing marriage and having families; today, South Korea has the lowest adolescent fertility rate, and the lowest overall fertility rate in the Asia Pacific region. Due to the current trajectory of South Korea's fertility rate, in January 2021, it was announced that the South Korean population experienced a natural decline for the first time in it's history.

South Korea: Buddhists as percent of the total population: The latest value from 2013 is 17.2 percent, a decline from 17.4 percent in 2012. In comparison, the world average is 36.4 percent, based on data from 21 countries. Historically, the average for South Korea from 1960 to 2013 is 20.2 percent. The minimum value, 17.2 percent, was reached in 2013 while the maximum of 21.4 percent was recorded in 1968.

Comparison in eGFR between participants revisit only in 2007 and those both in 2007 and 2010. (XLS)

We aimed to investigate the relationship between pesticide exposure and cognitive decline in a rural South Korean population. From July 2015 to December 2017, 200 randomly selected Korean Farmers Cohort study participants were recruited and of these, 169 participants were analyzed. Pesticide exposure was investigated using a standardized questionnaire, and the Korean-Montreal Cognitive Assessment (K-MoCA) was conducted. Cognitive decline was more frequent among those directly exposed to pesticides (P = 0.057). Pesticide exposure and cognitive decline were positively correlated in the group with direct exposure versus no exposure (crude odds ratio [OR], 2.66; 95% confidence interval [CI], 1.17–6.04); this relationship was insignificant after adjustment (adjusted OR, 1.50; 95% CI, 0.57–3.92). There was a significant difference in the K-MoCA scores for each group based on pesticide exposure (P = 0.003). When we stratified by age, differences in the K-MoCA scores depending on the degree of pesticide exposure in the those aged 60 to 69 years were identified. Overall, there was a tendency towards an association between pesticide exposure and cognitive decline in rural Korean adult farmers. In our study, chronic pesticide exposure tended to have a greater impact in certain age group (60–69 years) than in those under 60 and over 70.

In 2023, the annual population growth in South Korea amounted to 0.08 percent. Between 1961 and 2023, the figure dropped by 2.89 percentage points, though the decline followed an uneven course rather than a steady trajectory.

In 1900, the crude birth rate in South Korea was just under 42 births for every thousand people, meaning that approximately 4.2 percent of the population was born in that year. The crude birth rate would rise briefly in the 1930s, as Japanese investment would lead to economic growth on the peninsula, but would fall sharply in the 1940s, as the Second World War and the Korean War would result in two decades of significant socio-economic turmoil. While the crude birth rate would recover quickly after the end of the Korean War in 1953, a sharp decline in fertility beginning in the 1960s would see a corresponding fall in the crude birth rate lasting until the late 1980s, as South Korea would go through a rapid demographic transition and modernization. While the crude birth rate would briefly rise in the early 1990s, partially due to governmental restrictions on sex-selective abortion; the rate of decline would slow going into the 21st century. As a result, in 2020, it is estimated that South Korea has a birth rate of seven births for every thousand people, which is one of the lowest birth rates in the world.

Seagrasses provide numerous ecosystem services for coastal and estuarine environments, such as nursery functions, erosion protection, pollution filtration, and carbon sequestration. Zostera marina (common name "eelgrass") is one of the seagrass bed-forming species distributed widely in the northern hemisphere, including the Korean Peninsula. Recently, however, there has been a drastic decline in the population size of Z. marina worldwide, including Korea. We examined the current population genetic status of this species on the southern coast of Korea by estimating the levels of genetic diversity and genetic structure of 10 geographic populations using eight nuclear microsatellite markers. The level of genetic diversity was found to be significantly lower for populations on Jeju Island [mean allelic richness (AR) = 1.92, clonal diversity (R) = 0.51], which is located approximately 155 km off the southernmost region of the Korean Peninsula, than for those in the South Sea (mean AR = 2.69, R = 0.82), which is on the southern coast of the mainland. South Korean eelgrass populations were substantially genetically divergent from one another (FST = 0.061-0.573), suggesting that limited contemporary gene flow has been taking place among populations. We also found weak but detectable temporal variation in genetic structure within a site over 10 years. In additional depth comparisons, statistically significant genetic differentiation was observed between shallow (or middle) and deep zones in two of three sites tested. Depleted genetic diversity, small effective population sizes (Ne) and limited connectivity for populations on Jeju Island indicate that these populations may be vulnerable to local extinction under changing environmental conditions, especially given that Jeju Island is one of the fastest warming regions around the world. Overall, our work will inform conservation and restoration efforts, including transplantation for eelgrass populations at the southern tip of the Korean Peninsula, for this ecologically important species.

Context

Seagrasses provide numerous ecosystem services for coastal and estuarine environments, such as nursery functions, erosion protection, pollution filtration, and carbon sequestration. Zostera marina (common name "eelgrass") is one of the seagrass bed-forming species distributed widely in the northern hemisphere, including the Korean Peninsula. Recently, however, there has been a drastic decline in the population size of Z. marina worldwide, including Korea. We examined the current population genetic status of this species on the southern coast of Korea by estimating the levels of genetic diversity and genetic structure of 10 geographic populations using eight nuclear microsatellite markers. The level of genetic diversity was found to be significantly lower for populations on Jeju Island [mean allelic richness (AR) = 1.92, clonal diversity (R) = 0.51], which is located approximately 155 km off the southernmost region of the Korean Peninsula, than for those in the South Sea (mean AR = 2.69, R = 0.82), which is on the southern coast of the mainland. South Korean eelgrass populations were substantially genetically divergent from one another (FST = 0.061-0.573), suggesting that limited contemporary gene flow has been taking place among populations. We also found weak but detectable temporal variation in genetic structure within a site over 10 years. In additional depth comparisons, statistically significant genetic differentiation was observed between shallow (or middle) and deep zones in two of three sites tested. Depleted genetic diversity, small effective population sizes (Ne) and limited connectivity for populations on Jeju Island indicate that these populations may be vulnerable to local extinction under changing environmental conditions, especially given that Jeju Island is one of the fastest warming regions around the world. Overall, our work will inform conservation and restoration efforts, including transplantation for eelgrass populations at the southern tip of the Korean Peninsula, for this ecologically important species.

Content

Raw dataset of eight microsatellite loci for the 16 populations_Ramet Raw dataset (ramets sampled) of eight microsatellite loci for the 16 populations from Jeju Island and the South Sea in Korea

Raw dataset of eight microsatellite loci for the 16 populations_Genet Raw dataset (genets) of eight microsatellite loci for the 16 populations from Jeju Island and the South Sea in Korea

Acknowledgements

Kim, Jae Hwan et al. (2018), Data from: Population genetic structure of eelgrass (Zostera marina) on the Korean coast: current status and conservation implications for future management, Dryad, Dataset, https://doi.org/10.5061/dryad.v25c2

In 2024, Seoul's population amounted to around *** million, a decline from approximately *** million residents in the previous year. Seoul, the capital of South Korea, is one of the cities with the highest population densities in the world.

BackgroundAlthough previous studies have reported that frequent earphone use and lead exposure are risk factors for hearing loss, most of these studies were limited to small populations or animal experiments. Several studies that presented the joint effect of combined exposure of noise and heavy metal on hearing loss were also mainly conducted on occupational workers exposed to high concentration.ObjectivesWe investigated both the individual and joint effects of earphone use and environmental lead exposure on hearing loss in the Korean general population.MethodsWe analyzed data from 7,596 Koreans provided by the Korea National Health and Nutrition Examination Survey (KNHANES) during the period 2010–2013. The pure-tone average (PTA) of hearing thresholds at 2, 3, and 4 kHz frequencies was computed, and hearing loss was defined as a PTA ≥ 25 dB in one or both ears.ResultsA dose-response relationship in hearing loss with earphone use time and blood lead level is observed after adjustment for confounding factors. With a 1-hour increase in earphone use time and 1 μg/dL increase in blood lead concentration, the odds of hearing loss increased by 1.19 and 1.43 times, respectively. For hearing loss, the additive and multiplicative effect of earphone use and blood lead level were not statistically significant.ConclusionsEarphone use and environmental lead exposure have an individual effect on hearing loss in the general population. However, the estimated joint effect of earphone use and lead exposure was not statistically significant.

This account presents information on all aspects of the biology of Nervilia nipponica Makino (mukago-saishin) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the International Biological Flora: distribution, habitat, communities, responses to biotic factors, responses to the environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, conservation and global heterogeneity.

Nervilia nipponica is a small, stoloniferous, seasonally dormant herb that grows in the understorey of evergreen forests in the humid subtropical zone of central and western Japan, with a few outlying populations on Jeju Island in South Korea. Its northern extent is defined by the 0ºC winter isotherm, and its occurrence is also limited by site aspect and incline. It is a weak competitor that occupies species-poor microsites in which bare ground and leaf litter predominate. Plant numbers tend to decline as percentage ground cover of surrounding understorey vegetation increases.

The inflorescence sprouts from a short-lived, subterranean tuber in late spring and leaf-flush occurs after fruit-set. However, most tubers do not flower in any one annual growth cycle. Long-term monitoring of individually marked plants suggests that tubers are resource-limited and that flowering constrains future genet growth. Nervilia nipponica is exclusively autogamous and has a strong capacity for vegetative propagation. The species is genetically depauperate but exhibits significant differentiation between populations, which comprise clonal clusters in phalanx formation.

The level of mycorrhizal infection differs between plant parts and through successive phenological stages. Stable isotope signatures indicate that the species is partially mycoheterotrophic, with fungal partners supporting growth particularly at lower light intensities. Despite this, falling light availability associated with forest succession can lead to population decline.

Populations tend to be small and prone to extirpation, but the species is probably under-recorded as a result of its ephemeral emergence above ground and inconspicuous habit. Management interventions likely to benefit the species at the site level include thinning dense forest canopy and removing encroaching ground cover.

The tidal flats of the Kimberley coast support the largest populations of migratory shorebirds in Australia. Eighty Mile Beach and Roebuck Bay are the most important shorebird sites in the region, regularly supporting more than 550,000 migratory shorebirds. Shorebird numbers in north-western Australia have been monitored systematically since 2004, with the long-term objective of developing a dataset that can assess changes in shorebird diversity and numbers over time, and their response to environmental changes, such as local changes in coastal morphology, habitat loss (including that in staging areas), global population decline, climate change and sea-level rise. We seek to extend this monitoring program through the summer of 2012/2013. WAMSI funding was used to carry out two summer shorebird counts, 24-30 Nov 2012 and 9-14 Dec 2012, maintaining the continuity of a 14-year series of systematic counts from Eighty Mile Beach, Roebuck Bay and Bush Point. The data obtained will be added to the existing database, and used in two analyses/publications: (1) An assessment of whether dramatic declines in shorebird abundance in Korea following large-scale reclamation operations resulted in detectable effects in abundance and survival of shorebirds in northwestern Australia; (2) An assessment of whether shorebirds have changed their pattern of high tide roost use since 2004.

In 2021, the school-age population in South Korea comprises **** million people. This is a sharp decline from the 1980 population of **** million. It is expected that this trend of decline will continue, with projection of the 2060 school-age population comprising of only **** million people.

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