Earth Science

Human Impact on the Earth Environment

Agriculture and Human Population Growth

Study Tip
Some scientists think that the Earth can only contain 1 billion people. How do you think we are able to house 7 billion people on Earth today?

Hunters and Gatherers

  • Without agriculture, the population of the Earth would be limited to 10 million people.
  • Hunter gatherers were dependent on foraging and hunting around an area for resources, often having to migrate to survive.
Study Tip
Some scientists think that the Earth can only contain 1 billion people. How do you think we are able to house 7 billion people on Earth today?

Farming

  • About 10,000 years ago, humans developed the ability to farm, increasing the yield of food and allowing people to have food available year round.
  • Agriculture allowed people to settle down in one area, instead of having to migrate about in order to survive.
  • After settling down, people were able to produce more food and specialize in other trades.

The Industrial Revolution

  • During the 1700s, humans started using fossil fuels to power industries.
  • Products were first mass produced during this era, and the invention of machines aided food production.

The Green Revolution

  • The Green Revolution helped increase the amount of agricultural yield, making it possible for 1 farmer to feed up to 130 people.
  • Improved crops were produced through selective breeding and genetic engineering.
  • Fertilizers and pesticides were introduced into farming.
  • Machines took care of tasks such as plowing, tilling, fertilizing, picking, and transporting.
The development of agricultural machinery makes it possible for farmers to feed many people.

The Future

  • With more agriculture, people continue to use limited resources such as water.
  • Overpopulation is becoming a concern as we exhaust our resources.
Concept Check
  • What was made possible through agriculture?
  • How were populations limited by hunter gatherers?
  • What are the effects of the Green Revolution?