Is growth sustainable in africa is too wide and too vague of a question Mkuu Dingswayo -Chief of Mtetwa Kingdom (nearby Kwabulawayo Kingdom of the Zulu Kraal). Africa is way too big to try and generalize anything about it. Some countries have been able to sustain their groth over time while others have failed miserably.
All in all this querstion needs to be narrowed down to a specific country or region of the continent.
By the way say hello to Chief Mangosuthu wa Butelezi.