Human Impact

1
Human Impact
2
Human Population

• The 1 cause of all environmental problems
• Causes loss of habitat, increases in fossil fuel
  use and pollution, disrupting food chains and
  food webs

3
Acid Rain

• When nitrogen and sulfur compoundsfrom the
  burning of fossil fuels mix with water to form
  acid
• Can kill plants, dissolve and release toxic
  chemicals and make water more acidic, which kills
  plants and animals

4
Habitat Destruction

• Destroying habitats of plants and animals. Can be
  caused by many things especially human
  activities.
• Can lead to a reduced carrying capacity and
  eventually extinction.

5
Deforestation

• Destruction of loss of forests
• Caused by erosion, loss of nutrients, loss of
  habitats, decrease in the number of species
  (biodiversity)

6
Invasive (Non-Native) Species

• Species that are introduced to new habitats where
  they have no natural predators or parasites that
  limit the population growth, so they grow
  exponentially (think of the J-Curve!)
• A dangerous threat to biodiversity
• Examples Kudzu in the Southern US, zebra mussels
  in San Francisco, CA

7
Bioacculmulation and Biological Magnification

• When a chemical is introduced into the food chain
  and moves up through the trophic levels, becoming
  the most concentrated in the tertiary consumers
  (3rd-level consumers)
• Example DDT (pesticide) was used in farming
  until we realized it was killing large birds
  (Eagles, pelicans) because their eggs shells were
  so fragile that no babies were born!

8
Global Warming

• Global Warming an increase in the average
  temperature on the planet due to CO2 levels
• Could cause flooding, threats to distribution of
  species foods, extinction, weather pattern
  changes

9
Greenhouse Effect

• Greenhouse Effect natural situation where heat
  is trapped by CO2, methane, water vapor and other
  gases
• Photosynthesis helps remove CO2 from the
  atmoshphere which can help

10
Ozone Depletion

• Ozone acts like natural sunscreen for the earth
• Ozone Depletion lets more radiation (UV) rays
  through skin cancer and damage to plants and
  plankton
• Chlorofluorocarbons (CFCs) destroy the ozone
  layer
• Found in aerosol sprays, refrigerators

11
What can WE do?!

• The Future Food supply will be the limiting
  factor of the human population in the future. We
  will continue to have problems until we live in
  our environment sustainably
• Sustainable development using resources at a
  rate that does not deplete them and ensures no
  long-term environmental harm
• Sustainable development examples Reduce, reuse,
  recycle, use renewable sources of energy (solar,
  wind, etc), fuel-efficient cars, conserve
  electricity and water, grow and buy organic food,
  use public transportation