Hong Kong’s rolling political turmoil could prove a tipping point for the world economy, Harvard University economist Carmen Reinhart said.

Noting an incidence of shocks that have rattled global growth, including the intensifying U.S.-China trade war, Reinhart cited Hong Kong as among her main concerns. Having previously warned that Hong Kong faces a housing bubble, she said the world economy could be hit by “shocks with a bang or with a whisper.”

“One shock that is concerning me a great deal at the moment is the turmoil in Hong Kong,” which could impact growth in China and Asia generally, Reinhart said in an interview with Bloomberg Television’s Kathleen Hays.

“These are not segmented regional effects, these have really global consequences. So what could be a tipping point that could trigger a very significant global slowdown, or even recession -- that would be a candidate, that could be a candidate,” said Reinhart, who specializes in international finance.

Anti-government protests that began nearly three months ago are pressuring Hong Kong’s economy, which already was being squeezed by China’s slowdown and the trade war.

The academic’s warning comes days after Federal Reserve Bank of Boston President Eric Rosengren said Hong Kong’s crisis is on his global worry list.

“There are clearly problems in Hong Kong that could spill over in a broader sense into international markets,” Rosengren told Bloomberg Television this week. It’s “one of the great global cities so we do have to be concerned about how that all gets resolved.”

On Tuesday, U.S. Senate Majority Leader Mitch McConnell, who authored a 1992 law that granted special trading privileges to Hong Kong, wrote in the Wall Street Journal that the Senate “will reconsider that special relationship, among other steps, if Hong Kong’s autonomy is eroded.”

“The less dramatic part, but nonetheless very real, is already taking a situation that was weaker, where we have seen a slowdown of significant proportions, and just making it worse,” Reinhart said.

Economists say new tariffs that U.S. President Donald Trump has threatened on $300 billion of Chinese goods would drag China’s annual economic growth below 6%, according to a Bloomberg survey, which would be the slowest expansion since 1990.

“Tipping points don’t always need big drama,” Reinhart said.

This article was provided by Bloomberg News.