Worse-than-expected job losses will lead to rising inactivity and inequality.
Spain took the biggest hit, shrinking 18.5%, while French and Italian output also dropped by double digits.
Slowly but not surely, the world economy is emerging from its coronavirus-enforced hibernation.
Economists at Morgan Stanley and Berenberg expect the euro-zone GDP to shrink in the first half of the year.
Global trade declined for the first time in more than a decade in 2019 - and hopes for a better 2020 have faded with the rise of coronavirus.
A report cited a decline in U.S. trade openness and uncertainty among business leaders.
The downturn is ramping up pressure on governments to step up to the plate with fiscal stimulus.
Major factors have been Trump's election victory and the growth of China's economy.
There are, however, signs of stabilization in China.
Younger age groups are suffering from low wealth and a run of bad luck, the bank says.