"Operation Noah" is designed to highlight warnings that atmospheric warming from burning carbon fuels triggers violent weather patterns and rising sea levels.
Led by the Archbishop of York, David Hope; and the head of the Roman Catholic Church in England and Wales, Cardinal Cormac Murphy O'Connor; the campaign urges people to change their lifestyles to burn less fuel.
Human development is standing at a crossroads on the brink of ruining a fragile environment, the clerics said.
In July, the Archbishop of Canterbury, Rowan Williams, said heavy fuel use threatens the viability of humans as a species, and he called for a tax on greenhouse gas emissions.
Notable deaths of 2014 [PHOTOS]