We had lived our lives in linear economy where the emphasis was on consuming resource to make product, use the product and finally dispose it. As the number of people growing on earth this translates into need of more raw material, more manufacturing and this leads to more waste.

Linear economy was not a problem till the time our economies were small as compared to our eco system. But things were getting difficult from a point where our economies scaled up drastically and our eco system could not support it. In simple words what we are taking from eco system is much more than eco system generates in course of time. Also, we are making our eco system a dumping ground for non-biodegradable things.

Linear economies were supported by cheap energy, cheap raw materials and cheap credit available. But things are changing as resources are getting costlier, resource availability is also becoming harder, ecosystem is declining and financial system across world is getting complexed

So linear economies are not sustainable any more.

The efforts are ongoing to shift towards circular economy where the basic principle is to recover, reuse, generate less waste and use of renewable energies. The circular economy is operating system that should work like our natural eco system.

The circular economy is best depicted by ellen macarthur foundation butterfly diagram

https://www.ellenmacarthurfoundation.org/circular-economy/interactive-diagram