Human Impacts on the Environment

7SCIENCE

What are some ways that humans make an impact on the environment?

• Population growth• Pollution• Today we will learn about the following effects

humans have on the environment:– Farming and grazing– Deforestation– Landfills– Natural preserves

Farming and Grazing• Land is as important to people as clean air and

water:• Farming (agriculture)– Land is used to produce food for humans– Chemicals such as pesticides, herbicides and

fertilizers are used to increase productivity• Grazing – Land is also used to raise animals for human

consumption (e.g. cows = milk, meat)– Usually land that cannot be used for

farming

Deforestation

• Land is used as a resource for wood products

• Deforestation:– Trees are cut down for paper, fuel, or as

a building material– Trees SHOULD BE replanted, however

many forests in tropical regions are not being replaced

• Some studies suggest that up to 50 000 species could become extinct because they are losing their habitat (forest)

Landfills

• Land is also used for storing wastes from humans

• Landfill– Area where waste is

deposited

• Sanitary landfill is covered with dirt and this prevents waste from blowing away and reduces the odor (smell)– These landfills are lined with materials to prevent

liquid waste from going into the water and soil

Natural Preserves

• A natural preserve is land that is protected and not used by humans to produce something or to store waste– E.g. forests, national parks i.e. Parque Tayrona

• Land in its natural state is decreasing as human population increases

• WHY?

Introduction to the 3Rs

• The 3Rs represent the ideas to:– Recycle– Reduce– Reuse

• These 3 ideas can help to decrease the human impact on the environment

• How? Think of ways that the 3Rs can be applied to a human impact we learned about today in class