Demographic and Environmental Changes: c. 1900 - Present

AP Concept: 6.1 Science and the Environment
Key Concepts
  • Expanding population changed humans' relationship with their environment
  • Disease, scientific discoveries, and conflict led to demographic shifts
Demographic Changes
  • Scientific advances in the use of vaccines, antibiotics, and sophisticated sewage systems improved life expectancy rates
    • However, longer life expectancy and changing lifestyles led to a rise in diseases such as diabetes, heart disease, and certain kinds of cancer
  • The Green Revolution in agriculture transformed farming and fed the world's growing population
    • Birth rates in the developing world increased dramatically throughout the 20th century, despite birth control programs in India and the one-child policy in China
  • Migration increased in this period due to the growing population and lack of resources, as well as job opportunities elsewhere and political, religious, or ethnic persecution
    • Many people have moved to cities in rapid urbanization, which led to underemployment and the development of slums
    • External migrations have resulted in new cultural identities as well as anti-immigration movements
    • Conflict has led to great demographic shifts, as populations move to escape persecution in the Middle East
  • Epidemics have been able to spread more easily in this interconnected world, such as the 1918 influenza pandemic and AIDS
Environmental Changes
  • This huge population growth combined with rapid industrialization has led to significant environmental problems
  • Commercial overfishing has significantly depleted many oceanic fish species, leading to government regulation
  • Slash-and-burn agriculture and timber operations in tropical forests has resulted in deforestation
  • Water pollution destroys sources of fresh water, especially in developing nations
  • The use of petroleum and heavy metals has polluted the environment
  • The growing human population continues to generate greater amounts of trash, especially in industrialized societies mountains of non-degradable trash sit in landfills or are sent to developing nations
  • Scientists believe that human actions may have contributed to global warming of the environment
  • However, humans have begun to take a more positive approach to the environment, focusing on how they can protect and preserve our natural resources
  • Groups like Greenpeace and the Sierra Club work to protect the environment through direct action and government lobbying

Related Links:
AP World History Quizzes
AP World History
AP World History Notes
Scientific Discoveries: c. 1900 - Present