There is no waste in nature. Neither there are infinite resources in nature.
Then, how the natural processes have continued for so many years, without waste and without running out of resources.
Secret lies in the circular nature of the processes. Output of one system serves as input to some other system.
If we replicate this in the city, problem of waste management will be solved to a great extent.
Is it difficult? No, actually it is much easier than you think.
Here is an info-graphic explaining how we established leaf-exchange system at Brown Leaf and re-created the circle.