KEY IDEAh 255CHAPTER
31 Demographic and Environmental Developments
IN THIS CHAPTER
Summary:Although the Industrial Revolution generated overall improve-
ments in living standards, it also caused atmospheric pollution in indus-
trialized cities. Environmental challenges of the twentieth and twenty-fi rst
centuries included efforts to resolve poor environmental quality from indus-
trial and automobile emissions. Potential threats to the environment also
resulted from oil spills, the devastation of warfare, and the danger of melt-
downs from nuclear plants.
Since 1914, warfare, famine, disease, and migration have affected global
population distribution. Most migrants moved from developing to developed
nations in search of improved economic opportunities.Key Terms
Green Revolution* ozone depletion*
guest workers* xenophobia*The War Years
World War I resulted in the deaths of 10 million Europeans and eliminated nearly a generation
of young European men. The lack of potential husbands forced many European women to
remain unmarried. The drastic decline in marriages lowered the European birth rate and
population growth in future generations. Bombs and troop movements destroyed cities,
factories, and agricultural land. Another 35 million people lost their lives in World War II.
Because of postwar boundary changes, hundreds of thousands of displaced persons were
forced to relocate.http://www.ebook3000.com