The Limits of the Earth

acres agri agricultural algae Amazon Amazon Basin Amazonian American animals annual Argentina Australia Bantu become Belém Bering Sea birth rate Boer Brazil Brazilian British Canada cattle cent century Chlorella cities climate colonial commercial Congo Consequently continuing countries country's crops cultivation cultural diet drought earth East economic emigration Europe European existing export fact farmers farming fertility fish fishery flatfish food supply forests future half human hundred important improvement India industrial inner basin Iquitos labor land laterite latifundia limited living Manaus material ment million minerals nations natives natural ocean Pará plankton plant political ponds popu population growth possible potential pounds present problem production protein quantities rain rainfall recent regions result river Roman sablefish social soil South Africa square miles subsistence thousand tion tons trawling tropics United valley Western Western world World War II yields