Malthusianism is the theory that population growth is potentially exponential, according to the Malthusian growth model, while the growth of the food supply or other resources is linear, which eventually reduces living standards to the point of triggering a population decline. This event, called a Malthusian catastrophe occurs when population growth outpaces agricultural production, causing famine or war, resulting in poverty and depopulation. Such a catastrophe inevitably has the effect of forcing the population to "correct" back to a lower, more easily sustainable level. Malthusianism has been linked to a variety of political and social movements, but almost always refers to advocates of population control.
Thomas Robert Malthus, after whom Malthusianism is named
Oded Galor
Population decline, also known as depopulation, is a reduction in a human population size. Throughout history, 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.
An abandoned house in Yubari district, Hokkaido: an area which has suffered sharp population decline
Ukrainian refugees entering Romania, 5 March 2022
Thousands of abandoned villages are scattered across Russia.
Russian soldier killed in Ukraine. Vladimir Putin's war in Ukraine has further exacerbated Russia's demographic crisis.