Pope Francis walks next to Director-General of the United Nations Office at Nairobi (UNON) Sahle-Work Zewde, right, upon his arrival at the United Nations regional office, in Nairobi, Kenya, Thursday, Nov. 26, 2015. Pope Francis warned Thursday that it would be "catastrophic" for world leaders to let special interest groups get in the way of a global agreement to curb fossil fuel emissions as he brought his environmental message to the heart of Africa on the eve of make-or-break climate change talks in Paris. (Simon Maina/Pool Photo via AP)