Area appropriated is divided in categories of ecologically productive sectors, they are usually the following
• Fossil energy land, set aside for CO2 sequestration
• Arable land, producing crops (the ecologically most productive areas)
• Pasture, grazing land
• Forest, plantations or natural forests that may yield timber products and also provide many other ecological services.
• Built-up areas used for human settlements, roads, etc.
• Sea, where surface area determines the productivity of the sea.