GEF

Unit 2  |  Humanity’s Ecological Footprint 40 According to the U.S. Census Bureau, the world population doubled from 3 billion in 1959 to 6 billion by 1999. The world population is projected to grow to 9 billion by 2044. According to the United Nations, there are currently nearly 7.5 billion people on Earth. If trends continue, it is estimated the human population will rise to 9-12 billion people by the middle of the 21st century. Will Earth be able to support this many people? To answer this question, scientists are trying to understand Earth’s carrying capacity for the maximum human population. It is possible that no matter how many advances people make, at some point the number of people on Earth will reach a maximum amount for sustainability. World Population from 1950 – 2050. https://www.census.gov/ population/international/data/idb/worldpopgraph.php ?  DID YOU KNOW Even though hunter-gathers had little impact globally, archeological research indi- cates that prehistoric human settlement and deforesta- tion did have significant regional ecological impacts, permanently altering entire landscapes. For example, early agricultural settle- ments in the Middle East and Central America placed a heavy burden upon local natural resources, and some scholars blame the demise of many civilizations through- out history on unsustainable resource use.