REVIEW: Lesson Summary

Lesson Summary

Terraced farming helps keep soil from moving very far, limiting soil erosion on agricultural fields. Photo courtesy of CK-12. 

• The human population is growing more than exponentially
  
• The human population is increasing, the rate of human population growth is increasing, but the rate at which the rate of growth is increasing has declined
  
• The United Nations estimates a population of 10.1 billion by the end of the century
  
• Hunters and gatherers lived off the land, with no agriculture, and reached a total population of no more than around 10 million
  
• Farming allowed people to settle down and allowed populations to grow
  
• The Green Revolution and the Industrial Revolution are heavily dependent on fossil fuels
  
• The Green Revolution has allowed more people to be fed and the human population to increase. The consequences are land loss, pollution, and a tremendous use of fossil fuels and water
  
• By keeping more people alive, the Green Revolution has put a strain on other needed resources like water and materials
  
• Overpopulation is a big problem, but over-consumption is also depleting Earth's resources as some people in the world use far more materials than others
  
• Although soil erosion is a natural process, human activities have greatly accelerated it
  
• Soil erosion is more likely where the ground has been disturbed by agriculture, mining, grazing animals, logging and construction
  
• Soil is a renewable resource, but sometimes is lost faster than it can be replaced
  
• Soil resources must be preserved because there are many more people on EArth who need to eat and a great deal of topsoil has already been lost in many regions
  
• There are many techniques available for preventing soil loss in agriculture and grazing
  
• Soil conservation is extremely important. Some helpful practices include adding organic material, terracing and no-till farming
  
• The Green Revolution has also contributed to the scarcity of water resources. This has given rise to disputes between states and nations on how to manage water resources to meet the needs of increasing populations