For further reading:
Leather
Is it time to give up leather? (The Guardian)
The truth about leather (Animals Australia)
Circular Business
About circular business models (EU Sustainability Guide)
There are free courses and paid courses available for anyone interested in studying circular business/circular economy.
Lund University via Coursera is beginning their circular economy course today, with over 34k students registered. It's free.
TU Delft also has a free course via edX. You can register here.
Harvard has a paid extension course starting in January, with registration opening on Nov 8. About the course.