Nearly 50 pilgrims have set off on a 200-mile journey from London to Paris calling on world leaders to agree a fair, ambitious and binding climate deal at the United Nations Climate Change Conference (COP21) in Paris, following a service at St Martin in the Fields.
The campaigners will arrive in Paris on the 27 November 2015, as negotiators from more than 190 nations gather for the talks.
The pilgrimage has the backing of the Church of England, Christian Aid, CAFOD and Tearfund. Pilgrims will be staying in churches and in the houses of church members along the route.
To keep up-to-date with the progress of the pilgrimage see pilgrimage2paris.org.uk.
For more on the start of the pilgrimage see the Church of England website.