Climate change must be tackled through a coalition grounded in morality and ethics, the environment secretary, David Miliband, told a Vatican conference today. The conference was organised by Cardinal Renato Martino, who met Mr Miliband in London last November, when they discussed the importance of engaging faith communities in the battle against global warming. The British government has encouraged the Vatican to take a leading role in tackling climate change. It is hoped the Catholic church's influence over the world's 1.1 billion Catholics could be used to promote environmentally friendly changes in personal behavior.