The Environment Has Changed Through Time Humans change any environment they have inhabited by: -...
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Transcript of The Environment Has Changed Through Time Humans change any environment they have inhabited by: -...
The Environment Has Changed Through
TimeHumans change any environment they have inhabited by: - hunting - farming - developing the land
Manhattan, NYC 1609 vs. Manhattan, NYC 2009
Ex: The Extinction of Large Mammals
• At the end of the last Ice Age, many large mammals (like the Wooly Mammoth) became extinct in North America. Scientists are not exactly sure why large mammals went extinct, but the extinction coincides with the arrival of humans.
Think – Pair – Share:• 1) How might humans have contributed to the extinction?• 2) What other factors mighthave contributed to the extinction?
Human Changes to the Environment
Description Effects on Environm
ent
Effects on Society
Hunter - GathererAgricultur
al Revolutio
n
Industrial
Revolution
Spaceship EarthEarth has been compared to a ship traveling
through space
Earth is a closed system: - nothing comes in (except solar energy)- nothing goes out (except excess heat)
Problems:- some resources are limited- no where to put excess wastes
How big is the problem?• Although Earth is a complete system,
environmental problems can occur on different scales.Local – effects
individuals or small communitiesRegional – effects large areas potentially hundreds of miles apart (sections of countries or entire nations)Global – effects the entire world
Think – Pair - ShareCategorize the following environmental
problems as local, regional, or global:
1. A new landfill construction2. Township insect spraying3. Smog4. Release of ozone depleting chemicals5. Wildfires6. Excessive burning of fossil fuels
Why are environmental concerns pressing now
more than before? Human population growth increased
due to:– The Agricultural & Industrial Revolutions– Development of sanitation & modern medicine
Environmental concerns from population growth:
- Overuse of natural resources- Habitat destruction- Pollution
Main Environmental Problems
1- Resource DepletionNatural Resource – any natural material used by humans
- Renewable Resources – can be replaced relatively quickly by natural processes (plants, animals, air, water, soil, etc.)
- Nonrenewable Resources – form at a much slower rate than they are consumed - once it is used up, it will take millions of years to replenish it (fossil fuels, minerals, gems)
Main Environmental Problems
1- Resource Depletion•Resources are considered depleted when a large amount of the resource has been used up.
Deforestation Excessive Mining
Renewable or Nonrenewable?
• 1) Trees 5) Coal
• 2) Gold 6) Diamonds
• 3) Chickens 7) Notebook
• 4) Groundwater 8) Lightbulb
Main Environmental Problems2 - Pollution
• Pollution – an undesired change in air, water, or soil that negatively affects the health, survival, or activities of living organisms.– Biodegradable pollutants – can be
broken down by natural processes (ex: sewage, food waste)
– Nondegradable pollutants – cannot be broken down by natural processes (ex: mercury, lead, plastics)
Main Environmental Problems2 - Pollution
•Pollutants that do not break down easily can build up to dangerous levels in the environment
Air Pollution Water Pollution
Main Environmental Problems
3 – Loss of Biodiversity•Biodiversity – the number and
variety of species that live in an area– Endangered Species - a plant or
animal species existing in such small numbers that it is in danger of becoming extinct (ex: bald eagles)
– Mass Extinction – a large-scale coming to an end or dying out (ex: 250 mya, over 90% of all species became extinct)
Main Environmental Problems
3 – Loss of BiodiversityOnce they’re gone… they’re gone:
Humans are more dependent on species than they might know… we depend on organisms for food, oxygen to breathe, and potential economic, scientific, and recreational uses, among others.