It’s like a slinky… • Humans impact their physical environment and the physical environment impacts humans. • All human actions and all environmental changes have some impact on each other
For example… • In the 1920s, people in America started to move out West in greater numbers to farm. • They tore out the natural grasses to plant their crops. • There were not enough plants in the ground to hold in the soil • A very hot, dry summer in the 1930s led to dry ground and even less living plants in the ground with roots holding down the soil • Heavy winds blew the soil around the farms. It was like walls of dust. • The dust walls settled and buried the remaining plants, resulting in even less plants to hold down the soil… making the problem even worse. • Many Americans lost everything they owned and had to leave their homes and start over.
Three-Gorges Dam • The largest hydro-electric power station in the world • Located on the Yangtze River in China • Covered farmland, homes, and threatened wildlife when built
Think about your neighborhood… • 50 years ago • 100 years ago • 300 years ago • How have humans impacted the environment in this time? • How has the environment impacted humans in this time?