Humankind benefits in a multitude of ways from all kinds of ecosystems: agroecosystems, forest ecosystems, grassland ecosystems, aquatic ecosystems, natural ecosystems, urban ecosystems, etc. Collectively, these benefits are becoming known as ecosystem services. Ecosystem services are regularly involved in the provisioning of clean drinking water and the decomposition of wastes. While scientists and environmentalists have discussed ecosystem services implicitly for decades, the Millennium Ecosystem Assessment (MA) in the early 2000s popularized the concept. There, ecosystem services are grouped into four broad categories: provisioning, such as the production of food and water; regulating, such as the control of climate and disease; supporting, such as nutrient cycles and crop pollination; and cultural, such as spiritual and recreational benefits. To help inform decision-makers, many ecosystem services are being assigned economic values.
While the notion of human dependence on Earth’s ecosystems reaches to the start of homo sapiens’ existence, the term 'natural capital' was first coined by E.F. Schumacher in 1973 in his book Small is Beautiful . Recognition of how ecosystems could provide complex services to humankind date back to at least Plato (c. 400 BC) who understood that deforestation could lead to soil erosion and the drying of springs. Modern ideas of ecosystem services probably began when Marsh challenged in 1864 the idea that Earth’s natural resources are unbounded by pointing out changes in soil fertility in the Mediterranean. It was not until the late 1940s that three key authors – Henry Fairfield Osborn, Jr,William Vogt, and Aldo Leopold – promoted recognition of human dependence on the environment.