Rapid advances in science altered the understanding of the universe and the natural world and led to the development of new technologies. These changes enabled unprecedented population growth, which altered how humans interacted with the environment and threatened delicate ecological balances at local, regional, and global levels.
I. Researchers made rapid advances in science that spread throughout the world, assisted by the development of new technology.
A. New modes of communication and transportation virtually eliminated the problem of geographic distance.
B. New scientific paradigms transformed human understanding of the world.
Examples of new scientific paradigms: • The theory of relativity • Quantum mechanics • The Big Bang theory • Psychology
C. The Green Revolution produced food for the earth’s growing population as it spread chemically and genetically enhanced forms of agriculture.
D. Medical innovations increased the ability of humans to survive.
Examples of medical innovations: • The polio vaccine • Antibiotics • The artificial heart
E. Energy technologies including the use of oil and nuclear power raised productivity and increased the production of material goods.
II. As the global population expanded at an unprecedented rate, humans fundamentally changed their relationship with the environment.
A. Humans exploited and competed over the earth’s finite resources more intensely than ever before in human history.
B. Global warming was a major consequence of the release of greenhouse gases and other pollutants into the atmosphere.
C. Pollution threatened the world’s supply of water and clean air. Deforestation and desertification were continuing consequences of the human impact on the environment. Rates of extinction of other species accelerated sharply.
III. Disease, scientific innovations, and conflict led to demographic shifts.
A. Diseases associated with poverty persisted, while other diseases emerged as new epidemics and threats to human survival. In addition, changing lifestyles and increased longevity led to higher incidence of certain diseases.
Examples of diseases associated with poverty: • Malaria • Tuberculosis • Cholera
Examples of emergent epidemic diseases: • The 1918 influenza pandemic • Ebola • HIV/AIDS
Examples of diseases associated with changing lifestyles: • Diabetes • Heart disease • Alzheimer’s disease
B. More effective forms of birth control gave women greater control over fertility and transformed sexual practices.
C. Improved military technology and new tactics led to increased levels of wartime casualties.
Examples of improved military technologies: • Tanks • Airplanes • The atomic bomb
Examples of new tactics: • Trench warfare • Firebombing
Examples of wartime casualties: • Nanjing • Dresden • Hiroshima