"Here's my bet: the kids are going to win and when they do, it's going to matter," wagered the environmentalist Bill McKibben to Rolling Stone two years ago. He was on tour with a new campaign that was rapidly gaining traction on college campuses across the United States. Students were persuading their universities to withdraw their money from fossil fuels – the richest companies in the world.

Since McKibben's climate movement 350.org launched its fossil fuel divestment campaign in 2012, more than 220 institutions – including universities, faith organisations, local authorities, pension funds and foundations – have committed to divesting from fossil fuels.

Syracuse University is the largest so far. It committed in April 2015 to divest its $1.18bn (£800m) endowment and to seek new investments in clean energy technologies. The decision came a year after Stanford University committed to move out of coal investments.

In 2013 the Fossil Free campaign was launched in the UK. It highlighted the £5bn held in universities' endowments, with the first campaigns launching at Edinburgh, Birmingham and University College London. Yet it was the Quakers in Britain who became the first to divest in October that year.

By the end of the year, research by Oxford University suggested that it had become the fastest growing divestment campaign in history, surpassing those targeting the tobacco industry and apatheid in South Africa. The movement has only continued to accelerate.

The most symbolic announcement of all came in September 2014 as the heirs to Rockefeller oil fortune came on board, withdrawing the fossil fuel investments in the $860m Rockefeller Brothers Fund.