Download Human Impacts on the Environment and the 3Rs

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