14-7 How do human activities affect the balance of ecosystems?
Aim: How do human activities affect the balance of ecosystems?
OBJECTIVES: Explain ways humans harm the air, land, and water. Describe some steps humans
take to preserve ecosystems.
Key Terms
acid rain: rain containing acids produced by water chemically combining with certain gases
global warming: slow rise in Earth’s average temperature due to the buildup of harmful gases in the
atmosphere
conservation: wise use of natural resources
Lesson Summary
• Burning of fossil fuels produces carbon dioxide and other harmful gases.
• Water in the air combines with some of these gases to make acid rain.
• Carbon dioxide in the air traps heat and causes global warming.
• Litter, chemical wastes from industry, and fertilizers harm land and water.
• Deforestation reduces the amount of oxygen produced as well as the amount of carbon dioxide taken
out of the air.
• Nonnative species can upset the balance of ecosystems by out-competing native species for food and
shelter.
• Conservation, the wise use of natural resources, can make natural resources last longer.
OBJECTIVES: Explain ways humans harm the air, land, and water. Describe some steps humans
take to preserve ecosystems.
Key Terms
acid rain: rain containing acids produced by water chemically combining with certain gases
global warming: slow rise in Earth’s average temperature due to the buildup of harmful gases in the
atmosphere
conservation: wise use of natural resources
Lesson Summary
• Burning of fossil fuels produces carbon dioxide and other harmful gases.
• Water in the air combines with some of these gases to make acid rain.
• Carbon dioxide in the air traps heat and causes global warming.
• Litter, chemical wastes from industry, and fertilizers harm land and water.
• Deforestation reduces the amount of oxygen produced as well as the amount of carbon dioxide taken
out of the air.
• Nonnative species can upset the balance of ecosystems by out-competing native species for food and
shelter.
• Conservation, the wise use of natural resources, can make natural resources last longer.