In ecological footprint analysis, natural capital is usually defined as "all of the raw materials and natural cycles on Earth. Footprint analysis considers one key component, life supporting natural capital, or ecological capital for short. This capital is defined as the stock of living ecological assets that yield goods and services on a continuous basis." Also called nature's services. "Main functions include resource production (such as fish, timber or cereals), waste assimilation (such as CO2 absorption or sewage decomposition) and life support services (such as UV protection, biodiversity, water cleansing or climate stability)."