Population growthPopulation growth is the increase in the number of people in a population or dispersed group. Actual global human population growth amounts to around 83 million annually, or 1.1% per year. The global population has grown from 1 billion in 1800 to 7.9 billion in 2020. The UN projected population to keep growing, and estimates have put the total population at 8.6 billion by mid-2030, 9.8 billion by mid-2050 and 11.2 billion by 2100.
World populationIn demographics, the world population is the total number of humans currently living. It was estimated by the United Nations to have exceeded eight billion in mid-November 2022. It took over 200,000 years of human prehistory and history for the human population to reach one billion and only 219 years more to reach 8 billion. The human population has experienced continuous growth following the Great Famine of 1315–1317 and the end of the Black Death in 1350, when it was nearly 370,000,000.
Population declinePopulation decline, also known as depopulation, is a reduction in a human population size. Over the long term, stretching from prehistory to the present, Earth's total human population has continued to grow; however, current projections suggest that this long-term trend of steady population growth may be coming to an end. Until the beginning of the Industrial Revolution, the global population grew very slowly, at about 0.04% per year. After about 1800, the growth rate accelerated to a peak of 2.
Human population planningHuman population planning is the practice of managing the growth rate of a human population. The practice, traditionally referred to as population control, had historically been implemented mainly with the goal of increasing population growth, though from the 1950s to the 1980s, concerns about overpopulation and its effects on poverty, the environment and political stability led to efforts to reduce population growth rates in many countries.
Human overpopulationHuman overpopulation (or human population overshoot) describes a concern that human populations may become too large to be sustained by their environment or resources in the long term. The topic is usually discussed in the context of world population, though it may concern individual nations, regions, and cities. Since 1804, the global human population has increased from 1 billion to 8 billion due to medical advancements and improved agricultural productivity. Annual world population growth peaked at 2.
Income distributionIn economics, income distribution covers how a country's total GDP is distributed amongst its population. Economic theory and economic policy have long seen income and its distribution as a central concern. Unequal distribution of income causes economic inequality which is a concern in almost all countries around the world. Classical economists such as Adam Smith (1723–1790), Thomas Malthus (1766–1834), and David Ricardo (1772–1823) concentrated their attention on factor income-distribution, that is, the distribution of income between the primary factors of production (land, labour and capital).
Population ageingPopulation ageing is an increasing median age in a population because of declining fertility rates and rising life expectancy. Most countries have rising life expectancy and an ageing population, trends that emerged first in developed countries but are now seen in virtually all developing countries. That is the case for every country in the world except the 18 countries designated as "demographic outliers" by the United Nations. The aged population is currently at its highest level in human history.
Projections of population growthPopulation projections are attempts to show how the human population statistics might change in the future. These projections are an important input to forecasts of the population's impact on this planet and humanity's future well-being. Models of population growth take trends in human development and apply projections into the future. These models use trend-based-assumptions about how populations will respond to economic, social and technological forces to understand how they will affect fertility and mortality, and thus population growth.
Estimates of historical world populationThis article lists current estimates of the world population in history. In summary, estimates for the progression of world population since the Late Middle Ages are in the following ranges: Estimates for pre-modern times are necessarily fraught with great uncertainties, and few of the published estimates have confidence intervals; in the absence of a straightforward means to assess the error of such estimates, a rough idea of expert consensus can be gained by comparing the values given in independent publications.
Income inequality metricsIncome inequality metrics or income distribution metrics are used by social scientists to measure the distribution of income and economic inequality among the participants in a particular economy, such as that of a specific country or of the world in general. While different theories may try to explain how income inequality comes about, income inequality metrics simply provide a system of measurement used to determine the dispersion of incomes. The concept of inequality is distinct from poverty and fairness.
Population dynamicsPopulation dynamics is the type of mathematics used to model and study the size and age composition of populations as dynamical systems. Population dynamics has traditionally been the dominant branch of mathematical biology, which has a history of more than 220 years, although over the last century the scope of mathematical biology has greatly expanded. The beginning of population dynamics is widely regarded as the work of Malthus, formulated as the Malthusian growth model.
Extreme povertyExtreme poverty is the most severe type of poverty, defined by the United Nations (UN) as "a condition characterized by severe deprivation of basic human needs, including food, safe drinking water, sanitation facilities, health, shelter, education and information. It depends not only on income but also on access to services". Historically, other definitions have been proposed within the United Nations. In 2018, extreme poverty mainly refers to an income below the international poverty line of $1.
PovertyPoverty is a state or condition in which one lacks the financial resources and essentials for a certain standard of living. Poverty can have diverse social, economic, and political causes and effects. When evaluating poverty in statistics or economics there are two main measures: absolute poverty compares income against the amount needed to meet basic personal needs, such as food, clothing, and shelter; relative poverty measures when a person cannot meet a minimum level of living standards, compared to others in the same time and place.
Redistribution of income and wealthRedistribution of income and wealth is the transfer of income and wealth (including physical property) from some individuals to others through a social mechanism such as taxation, welfare, public services, land reform, monetary policies, confiscation, divorce or tort law. The term typically refers to redistribution on an economy-wide basis rather than between selected individuals. Interpretations of the phrase vary, depending on personal perspectives, political ideologies and the selective use of statistics.
International inequalityInternational inequality refers to inequality between countries, as compared to global inequality, which is inequality between people across countries. International inequality research has primarily been concentrated on the rise of international income inequality, but other aspects include educational and health inequality, as well as differences in medical access. Reducing inequality within and among countries is the 10th goal of the UN Sustainable Development Goals and ensuring that no one is left behind is central to achieving them.
Climate change and povertyClimate change and poverty are deeply intertwined because climate change disproportionally affects poor people in low-income communities and developing countries around the world. The impoverished have a higher chance of experiencing the ill-effects of climate change due to the increased exposure and vulnerability. Vulnerability represents the degree to which a system is susceptible to, or unable to cope with, adverse effects of climate change including climate variability and extremes.
Human historyHuman history is the narrative of humankind's past. Humans evolved in Africa 300,000 years ago and initially lived as hunter-gatherers. Humans migrated out of Africa during the Last Glacial Period (Ice Age) and had populated most of the Earth by the time the Ice Age ended 12,000 years ago. The Agricultural Revolution began soon afterwards in fertile river valleys of the Near East: humans began the systematic husbandry of plants and animals, and many humans transitioned from a nomadic life to a sedentary existence as farmers in permanent settlements.
History of geographyThe history of geography includes many histories of geography which have differed over time and between different cultural and political groups. In more recent developments, geography has become a distinct academic discipline. 'Geography' derives from the Greek γεωγραφία – geographia, literally "Earth-writing", that is, description or writing about the Earth. The first person to use the word geography was Eratosthenes (276–194 BC). However, there is evidence for recognizable practices of geography, such as cartography (map-making), prior to the use of the term.
GeographyGeography (from Greek: γεωγραφία, geographia. Combination of Greek words 'Geo' (The Earth) and 'Graphien' (to describe), literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding of Earth and its human and natural complexities—not merely where objects are, but also how they have changed and come to be.
Distribution of wealthThe distribution of wealth is a comparison of the wealth of various members or groups in a society. It shows one aspect of economic inequality or economic heterogeneity. The distribution of wealth differs from the income distribution in that it looks at the economic distribution of ownership of the assets in a society, rather than the current income of members of that society. According to the International Association for Research in Income and Wealth, "the world distribution of wealth is much more unequal than that of income.
