"We are already witnessing an unbearable catastrophe with the fighting in Blue Nile and South Kordofan in Sudan, and the ensuing outpouring of refugees into South Sudan and Ethiopia."

Writing from Addis Ababa at the start of an Elders delegation to Sudan and South Sudan, Desmond Tutu blogs for CNN about the region's urgent humanitarian needs and what he hopes the Elders can achieve on their visit.