Global life expectancy has more than doubled in a century.

Left: average life expectancy at birth worldwide (years). Right: deaths before age five, per 1,000 births. As child mortality collapsed from over 360 to under 40, average lifespans rose from 32 years to 73.

Why this is happening

Most of the early gain came from cutting child deaths through clean water, sanitation and vaccines.
Antibiotics and the spread of basic health care from the mid-century pushed survival into old age across poorer countries.
The dip in 2021 was Covid, the first global reversal in decades, and it has since recovered.

The take

A baby born today can expect more than double the life of one born in 1900, and almost all of that came from keeping children alive, not from the old living much longer. The two lines are one story: as child deaths collapsed, average lifespans soared.

Source: UN, Our World in Data