ABSTRACT
Urbanization is the pre-eminent global phenomenon of our time. Currently, urban areas account for 75% of the world's natural resource consumption, while producing over 50% of the globe's waste on just 2–3% of the earth's land surface. Without recycling, cities will continue to constitute vast sinks for food waste including valuable crop nutrients and organic matter, while millions of rural, peri-urban or urban farmers struggle with depleted soils to feed the growing urban population. While Europe continues setting an example with the implementation of a first action plan on the circular economy, more attention should be given to natural resource loops in low- and middle-income countries, especially in the tropics where soils are poor and nutrient depletion is high and commercial fertilizer is basically unaffordable. Given the common situation of the waste and sanitation sectors, especially in Africa and Asia, the term 'business models' might appear to be out of place.
