An important aspect of the concept is the link between the ecosystem (nature) and the welfare of people, and thus society as a whole. This relationship is shown in figure 2. It further emphasises that changes we implement in society - the socio-economic system - influence nature, and this again will impact the quality and quantity of the services we receive from nature. For example, the reports covering fresh and salt water show how pollution from sewage, industry and agriculture affects the quality of fresh and salt water, respectively.