Islamic scholars and religious leaders are preparing a call for action on climate change that will say it's the religious duty of the world's 1.6 billion Muslims to fight global warming. The declaration will be made in Istanbul next Tuesday during a two-day meeting in the Turkish city coordinated by three religious-environmental groups, according to Climate Action Network, a network of non-governmental organisations. A growing list of religious leaders have made interventions on climate change to spell out the moral imperative to reduce man-made greenhouse-gas pollution and prevent the worst effects of climate change. Foremost was Pope Francis, the spiritual leader of 1.2 billion Catholics.