There are more young people than ever before. About 41% of the global population of 7.7 billion is aged 24 or under. In Africa, 41% is under 15. In Asia and Latin America (where 65% of the world’s people live), it’s 25%. In developed countries, imbalances tilt the other way. While 16% of Europeans are under 15, about 18%, double the world average, are over 65.

Perhaps these protests will merge into international revolt against injustice, inequality and oppressive powers-that-be.

Most of these young people have reached, or will reach, adulthood in a world scarred by the 2008 financial crash. Recession, stagnant or falling living standards, and austerity programmes delivered from on high have shaped their experience. As a result, many current protests are rooted in shared grievances about economic inequality and jobs. In Tunisia, birthplace of the failed 2011 Arab spring, and more recently in neighbouring Algeria, street protests were led by unemployed young people and students angry about price and tax rises – and, more broadly, about broken reform promises. Chile and Iraq faced similar upheavals last week.

This global phenomenon of unfulfilled youthful aspirations is producing political timebombs. Each month in India, one million people turn 18 and can register to vote. In the Middle East and North Africa, an estimated 27 million youngsters will enter the workforce in the next five years. Any government, elected or not, that fails to provide jobs, decent wages and housing faces big trouble.