Transcript Global Issues

Global Issues
BIOLOGY CH 6
The Effect of Human Activity
How
do our daily
activities affect the
environment?
Environmental Problems CAUSED by
HUMANS
 Rapid population
growth
More humans = more
needs
We Need Food,
Water, Shelter
All resources come
from the environment
Pollution
 Humans are
increasing the levels of
pollution in the
environment
 Causes cancer in
humans and
animals
 Leads to the
extinction of many
species
Atmospheric Pollution
 Increase in carbon dioxide
pollution caused by
burning fossil fuels
 Global temperatures
are increasing
 Polar ice caps are
melting and Sea levels
are rising
 Holes in atmosphere
are allowing in more
ultraviolet light 
leads to mutations
(skin cancer)
Oceanic Pollution
 Eutrophication
occurs when excess
nutrients run off
into the
environment
 Examples:
Chemical and oils
spills
Biological Magnification
 Occurs when toxic
chemicals accumulate in
the tissues of organisms
 Example: (DDT)
dichlorodiphenyltrichl
oroethane is a
pesticide used to kill
insects, but has
negative effect on
birds and other
organisms
The Value of Biodiversity
Why
is
biodiversity
important?
The Value of Biodiversity
•
•
Total of all the genetically based variation in all
organisms in the biosphere is called biodiversity
Types of biodiversity:
o Ecosystem diversity (variety of habitats &
communities)
o Species diversity (1.8 million species & 30 million
yet to be discovered)
o Genetic diversity (genes present in a species)
Problem: Biodiversity Crisis
 More species are going extinct now than in the past
100 thousand years
HUMANS Threat BIODIVERSITY
By:
• Altering
habitats 
Deforestation &
Habitat
fragmentation
(clear land for
farming, housing
decreases biodivesity)
HUMANS Threat BIODIVERSITY
By:
• Overharvesting
 killing wild
organisms at a
rate greater than
the population
can replenish
HUMANS Threat BIODIVERSITY
By:
• Introducing
invasive
species  nonnatives species
compete for
food and space
HUMANS Threat BIODIVERSITY
By:
• Releasing pollution into
food webs  biological
magnification (Pesticides
& Acid Rain)
• Trying to “fix it”
Farmers using less
pesticides
Alternative energy sources
are being looked at.
HUMANS Threat BIODIVERSITY
By:
• Contributing to
climate change 
global warming
Trying to “fix it”
• Need to buy cars with
good gas mileage, find
alternative energy
sources, protect
forests (natural CO2 absorbers)
HUMANS Increase Biodiversity
•
•
•
Wildlife protection of species
Researching the needs of organisms and their
interactions
Preserving forest and wetland habitats and ecosystems
Re-introduction of a native species will increase
biodiversity
Sustainable Development
What
is the relationship
between resource use
and sustainable
development?
Sustainable Development
•
Using natural resources in a way that does not
cause long-term environmental harm is called
sustainable development
• causes no long-term harm to the soil, water, and
climate on which it depends
• consumes as little energy and materials as
possible.
• flexible enough to survive environmental stresses
like droughts, floods, and heat waves