When I met Giles Goddard, Priest in Charge of St John’s Church, Waterloo, in February this year he was at the end of a busy week. The General Synod of the Church of England had voted 274 to 1 in favour of a motion he had brought, one tenet of which committed the Church to align its investment portfolio with its ethical commitments concerning tackling climate change.

Giles is the pastor of a parish that includes the headquarters of Shell. When Siobhan Grimes, a member of his congregation and then campaigner with Climate Rush, took issue with Shell’s sponsorship of the summer festival at St John’s, a conversation began between her and Giles that led, three years later, to the Synod’s vote. “I didn’t even realise that faith institutions have investments in fossil fuels,” Siobhan told me, “and then I discovered it was normal for institutional investors to have huge investments in things that don’t quite match up with the world they’re meant to be in.”

Not for much longer, perhaps. A campaign launched by 350.org to persuade investors to remove their money from the fossil fuel industry is, according to a recent study by the University of Oxford, the fastest-growing divestment campaign in history. In less than a year it has found strong support across the US, Europe and Australasia, with hundreds of university campuses, organisations, philanthropic institutions and cities committing to divest, and now it is garnering the attention of religious institutions.

The economic arguments for divestment are persuasive. Carbon Tracker Initiative, a London-based group of financial analysts, has highlighted the potential for fossil fuel investments to wind up as stranded assets if targets for global emission reductions become mandatory and reserves become unburnable. The Church of England, with a portfolio of £9 billion, is small fry, but everyone from HSBC to the World Bank is starting to take note. And whilst the resulting impacts upon the fossil fuel industry are unlikely to break the bank, a recent report by academics at the Smith School of Enterprise and the Environment, University of Oxford points out that indirect impacts could be widespread. “The outcome of the stigmatisation process, which the fossil fuel divestment campaign has now triggered, poses the most far-reaching threat to fossil fuel companies,” say the academics.

Both Siobhan and Giles are trustees of Operation Noah, an ecumenical charity running the Bright Now campaign, which is calling for all UK churches to divest from fossil fuel companies. There is widespread excitement amongst everyone I spoke to, a sense that a strong stance on climate change could push the Church into a position of relevance, which it currently struggles to hold.

Giles believes that the Church has powerful reasons to be engaging with climate change. “We kind of have it in our manifesto,” he told me. “We care about justice, and clearly this is a justice issue because of the way it affects those who’ve contributed to it much less than it affects those who haven’t. But it is also about how we look after Creation. Stewardship is about making sure that the whole of the planet is properly cared for.” For Siobhan it is about authenticity. “If churches make their decisions purely based on financial returns,” she said, “then what makes a church a church, if it’s not trying to live up to some gospel value?”

If such discussion seems ideological when faced with the cold reality of making a profit, then the Quakers are proving it is possible. In 2011 they made a national commitment to become a low-carbon community. That, says Sunniva Taylor, Programme Manager of Sustainability for Quaker Peace & Social Witness, raised questions around investment. “Is it right for us to benefit from damaging the Earth in the way we use our money?” she asks. “Quakers try and put their lives under the guidance of the spirit. The whole life needs to be governed by what the spirit is guiding us to do, and that includes the finances. Through our money we can witness to our beliefs and our commitments.” The Quakers had finished divesting their portfolio by last Christmas.

Beyond its importance for their own integrity, the move has, Sunniva believes, enabled other religious groups to contemplate following suit. From the Anglican Church in New Zealand, to the Diocese of California, to the Church of Scotland, discussions are spreading with a rapidity matched by the campaign’s take-up in the secular world. In July, the World Council of Churches, a fellowship of 300 churches representing 590 million people, voted in favour of divestment, a decision hailed by 350.org as perhaps their most important commitment to date. “I think talking about money is a really good way in to connect the personal and the political and the systemic,” says Sunniva. “Through money we can start talking about things that are a lot bigger than ourselves.”

As I finish my conversation with Siobhan she speaks to me of prophecy. “There’s this whole idea in churches of being prophetic,” she says, “which means speaking the truth. In order for churches to be prophetic we have to talk about things like climate change and money. The Bible says an awful lot about money; that money can be used to exploit the poor. It’s at the heart of Christianity, and so I’m sure divestment will happen. It’s an untenable situation to continue to be in.”

In the temples, it seems, the tables of the fossil fuel companies are being overturned.

Adam Weymouth is a freelance writer. www.adamweymouth.com @adamweymouth