Period· The columns of time

Contemporary

1800 → Today

The contemporary period opens with industrialisation around 1800 and has no closing date.

Period opened with industrialisation around 1800 and without closing limit. Human population is multiplied by eight, life expectancy at birth approximately doubled, and the combustion of fossil carbon modifies the composition of the atmosphere measurably in ice archives.

What the evidence shows

In 226 years, human population moves from about one billion to eight billion. The doubling of life expectancy calls for a qualification, since this measure is an average of ages at death and not the lifespan of an adult. When one child in three died before the age of five, that average stood around thirty years without adults being elderly: a person reaching twenty could then expect some forty further years. The rise in the figure therefore proceeds first from the fall in infant mortality and not from an equivalent lengthening of old age. Referred to the scale of the timeline, this band represents about seven hundredths of one per cent of the existence of the species, a proportion to be held together with the scale of the transformations it contains.

Bounds and conventions

This is the only band without a closing limit. Its opening date is conventional and varies with author and country, from the 1780s to the 1850s, according to whether the periodisation takes machines, fuel, political institutions or demography as its criterion.

Since 1800. Historiographical convention.