Polar bears are important not only for their beauty but for being at the top of the Arctic food chain. But pollutants carried to the High Arctic by winds and ocean currents threaten the bears - another victim of climate change.

Right-wing campaigners and journalists reviving denial of human-made climate change are facing strong criticism from scientists, academics and NGOs. They are accused of trying to derail the Copenhagen climate summit.

The climate-change campaign needs a sense of can-do enthusiasm, says Giles Fraser. It would be really something if faith leaders were able to help replace gloomy defeatism with a broader version of something Christians call hope.

Leaders of nine major faiths have presented 60 ideas for lessening carbon emissions to the United Nations after the Secretary-General, Ban Ki-moon, singled out the religious community as key in fighting climate change.