A spike in food prices. We can probably weather it OK in the developed world, but last time something like this happened it helped kick off the Arab Spring. Abrupt, large changes in quality of life tend to spark revolutions. They usually get people killed, and often don't result in a more-liberal government taking power.
Also these aren't just minor increases, e.g. Allianz estimate a 31% increase in prices in 2021; for people who live hand to mouth in the developing world this is catastrophic.
> Pastocalle has been a flash point of protests called by the powerful Confederation of Indigenous Nationalities of Ecuador (Conaie) against rising fuel prices and living costs, which saw protesters block roads across the country on Monday.
As a result of the Russian invasion of Ukraine, their destruction if Ukrainian agriculture, their blockade of Ukrainian ports, and sanctions on Russia (which don't cover foodstuffs)*