Sept 4( Reuters)-At the African Climate Summit this week, national leaders meet to discuss how to fund the challenges posed by climate change and biodiversity loss. Deals worth hundreds of millions of dollars are expected to be signed at the three-day conference in Nairobi that began on Monday, although the total is set to remain a long way short of what is needed. Below are some of the various ways in which countries can finance protection of their natural resources-and the potential hurdles to