High youth unemployment in Europe and disappointing growth expectations in the emerging world could mean more mass protests like the ones seen in Brazil, Niall Ferguson told CNBC's "Power Lunch" on Tuesday.
"There are two kinds of city that we could see burn this summer," Ferguson said. "The big European cities with Paris at the top of the list look extremely vulnerable. Paris has a greater tradition of urban rioting than almost any city in the world."
Ferguson, a Harvard University professor, said the French economy is bad and "the youth unemployment problem right across Latin Europe is really an explosion waiting to go off."
There could also be trouble win big emerging market cities where the rising expectations are about to be disappointed, he said.
Protests have already begun to spring up in Brazil. "The economy has been doing less well of late," Ferguson told CNBC. "Young people have got used to rising living standards, inequality has been coming down somewhat from its extraordinary terrible heights. And now as the economy slows down the frustration boils over because people's expectations were rising and now they're disappointed."
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China also bears watching. Ferguson said he spent April in China and said the government is worried about social unrest. "The leadership are really seriously worried about the possibility of revolution," he said. Ferguson's host in China told him that some of they country's leaders are reading Toqueville's "Old Regime and the Revolution."
"They think they're 18th century France," Ferguson said.
"But my guess is they have better handle on this than their counterparts in Brazil," he added. "If there's one thing the Chinese communists do pretty well, it's public order. They run a pretty efficient police state."