Efficiency vs. Sustainability?

The recent months have been so busy with exhilarating complex work; I hardly find any time to share any of the many inspiring thoughts I keep coming across! Here is a beautiful one: is efficiency good for sustainable development? As Robert Lukesch, a regional development specialist, pointed out at a recent DeGEval conference (German Evaluation Association), redundancy, i.e. having more than one set of resources to perform a certain activity, is a vital feature in living organisms and ecosystems. For example, we have two kidneys so that we can continue to live if one of them fails.