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.
History of medicineThe history of medicine is both a study of medicine throughout history as well as a multidisciplinary field of study that seeks to explore and understand medical practices, both past and present, throughout human societies. The history of medicine is the study and documentation of the evolution of medical treatments, practices, and knowledge over time. Medical historians often drawn from other humanities fields of study including economics, health sciences, sociology, and politics to better understand the institutions, practices, people, professions, and social systems that have shaped medicine.
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.
Northern AmericaNorthern America is the northernmost subregion of North America. The boundaries may be drawn slightly differently. In one definition, it lies directly north of Middle America. Northern America's land frontier with the rest of North America then coincides with the Mexico–United States border. Geopolitically, according to the United Nations' scheme of geographical regions and subregions, Northern America consists of Bermuda, Canada, Greenland, Saint Pierre and Miquelon and the United States (the contiguous United States and Alaska only, excluding Hawaii, Navassa Island, Puerto Rico, the United States Virgin Islands, and other minor U.
Little Ice AgeThe Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region. It was not a true ice age of global extent. The term was introduced into scientific literature by François E. Matthes in 1939. The period has been conventionally defined as extending from the 16th to the 19th centuries, but some experts prefer an alternative timespan from about 1300 to about 1850. The NASA Earth Observatory notes three particularly cold intervals.
PrehistoryPrehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5,000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century.
Afro-EurasiaAfro-Eurasia (also Afroeurasia, Eurafrasia, Africa-Eurasia or the Old World) is a landmass comprising the continents of Africa, Asia, and Europe. The terms are compound words of the names of its constituent parts. Its mainland is the largest and most populous contiguous landmass on Earth. Afro-Eurasia encompasses , 57% of the world's land area, and has a population of approximately 6.7 billion people, roughly 86% of the world population.
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.
Human migrationHuman migration is the movement of people from one place to another with intentions of settling, permanently or temporarily, at a new location (geographic region). The movement often occurs over long distances and from one country to another (external migration), but internal migration (within a single country) is also possible; indeed, this is the dominant form of human migration globally. Migration is often associated with better human capital at both individual and household level, and with better access to migration networks, facilitating a possible second move.
Thomas Robert MalthusThomas Robert Malthus (ˈmælθəs; 13/14 February 1766 – 29 December 1834) was an English economist, cleric, and scholar influential in the fields of political economy and demography. In his 1798 book An Essay on the Principle of Population, Malthus observed that an increase in a nation's food production improved the well-being of the population, but the improvement was temporary because it led to population growth, which in turn restored the original per capita production level.
