Faith leaders have a vital role to play in inspiring politicians to act "more courageously" at next month's critical Copenhagen climate summit, the United Nations Secretary-General has said.

The major religions are in a "unique" position to influence discussions on global warming, Ban Ki-moon told an audience of 200 faith and community leaders at Windsor Castle.

"Science has made it quite clear - plainly clear - that this climate change is happening and accelerating much, much faster than one realises," he told his audience.

"We have know-how, we have resources but the only vacuum is political will.

"You can inspire, you can provoke, you can challenge your leaders, through your wisdom, through your followers.

"Together let us walk a more sustainable path, one that respects our planet and provides for a safer, healthier, more equitable future for all."

The UN Secretary-General said he welcomed long-term action plans on the environment announced by nine of the world's major faiths - Baha'ism, Buddhism, Christianity, Daoism, Hindu, Islam, Judaism, Shintoism and Sikhism.

The Grand Mufti of Egypt, Sheikh Ali Goma'a, announced that Madinah, one of Islam's most important cities, is to become a model "green city" under a Muslim seven-year action plan on the environment.

The conference was organised by the Alliance of Religions and Conservation (ARC), and the United Nations Development Programme.

The Duke of Edinburgh, ARC founder, presented certificates to faith leaders alongside the UN Secretary-General.