The retirement age should rise to at least 70 in rich countries by 2050 as life expectancy rises above 100, according to a new report.
The World Economic Forum said that employees should continue working until 70 in nations such as the UK, US, Japan and Canada.
The increase will be needed, as the number of people over 65 will more than triple to 2.1 billion by 2050.
By then, the number of workers per retiree will have halved to just four.
Michael Drexler, head of financial and infrastructure systems at the World Economic Forum, said the expected rise in longevity was the financial equivalent of climate change.
“We must address it now or accept that its adverse consequences will haunt future generations, putting an impossible strain on our children and grandchildren,” he said.
In the UK the state pension age is due to rise from 65 in 2018 to 68 by 2046.