The best way to simulate reducing waste or inefficiency in En-ROADS is to adjust the following sliders:

1. Buildings and Industry Energy Efficiency (less energy is used to produce new materials and goods)

2. Transport Energy Efficiency (less energy is used to transport materials, products, and waste)

3. Methane and Other, adjusting advanced settings of "Agriculture and waste emissions" (reduced methane emissions from waste) and “Energy and industry emissions” (reduced methane emissions from industrial processes)

Sometimes the slider settings may not match exactly what you are trying to model, but the overall idea is comparable.