Christians of all denominations will be among the thousands expected to march in London on Saturday 4 November on the eve of critical international climate change talks in Nairobi.
They will join the march leading to the 'I Count' rally in Trafalgar Square organized by the Stop Climate Chaos coalition, which includes a wide range of environment, development and faith organizations.
One gathering point for Christians who care about climate justice will be a service at in Grosvenor Chapel, Audley Street, London. The service is organized by Operation Noah which was set up by Churches Together in Britain and Ireland and Christian Ecology Link.
The Anglican Bishop of Liverpool, the Rt Revd James Jones is encouraging Christians to stand up and be counted. He said: "Climate change is already having an impact in many parts of our world. The people with the power to act are the most protected from feeling its impact: while the most vulnerable often feel powerless to do anything about it. Working with developing countries on trade and aid is undermined if we change the climate and ruin their harvests. Today the Churches, together with Operation Noah, are calling on governments to acknowledge the urgency of the crisis and agree bold measures to limit carbon emissions."
Churches are also being urged to join individuals and businesses and take part in a blackout in London as part of a night of "non-power" in the nation's capital.
Known as "Blackout London", the powerdown is being called at Sunset from 4.30 pm until 7.30 pm on 4th November. People, churches, businesses, and public buildings are all being asked to turn out the lights and switch off unessential equipment at this time, with the aim of increasing 'negawatts' (and reducing megawatts) at local power stations.
Big London landmarks are a target - including the thousands of church buildings in the capital.
A special prayer will be put on the Operation Noah website for churches throughout Britain and Ireland to use to show their commitment on 5 November. It has been written by the Revd David Pickering, Moderator of the Operation Noah Executive Committee.