2 Ways in which biodegradable substances would affect the environment are-

• Composting is a common method used to degrade biodegradable materials. In a compost pit, the organic materials get converted into fertilizers/ manures. These fertilizers and manures add to the fertility of the soil and improve the humus content of the soil.

• Biodegradable substances when decompose emit gases like ammonia, CO2 & methane; carbon dioxide methane are greenhouse gases, hence they cause an increase in global warming.