1. AGRICULTURE and HUMAN IMPACT on the BIOSPHERE Chapter 6

2. HUMAN POPULATION You are here

3. WORLD POPULATION Current world population is just over _____________
World clock
Current world population is just
over _____________
Estimates predict it will reach billion by 2050

4. Does this look familiar?
What is the Earth’s carrying capacity?

5. SUSTAINABILITY How can we grow enough food for all the people on the planet without destroying the environment?

6. Importance of Agriculture
By middle of 20th century, despite agricultural advances there were ________________in many parts of the world.
Governments and scientists began a major effort to ___________ food production

7. __________ REVOLUTION
New plant ________ had higher yield & resisted pests
2. Modern farming__________
allowed planting larger areas
3. Chemical ___________ & ___________ boosted crop production and controlled pests

8. HOW DO WE GROW MORE FOOD? Large fields are planted with a
single variety
year after year
= ____________

9. Allows farmers to grow large quantities of food BUT . . .
MONOCULTURE
Allows farmers to grow large quantities of food BUT . . .

10. But . . . HAS HUGE IMPACT ON ECOSYSTEMS
__________ increase yield BUT RUNOFF can cause algal blooms and ____________

11. But . . . HAS HUGE IMPACT ON ECOSYSTEMS
________ kill insects that damage crops BUT . . .
they kill ________ insects too
Bees
Hand pollination

12. _____ was first modern insecticide
Example:
_____ was first modern insecticide
It was cheap, stayed active for long time, and killed many different insects
Used to control agriculture pests
and disease carrying
_______________

13. http://www. ci. cypress. ca
When DDT was sprayed,
runoff carried it into rivers
and streams in LOW
concentrations.
DDT then passes into
organisms through the
___________, is stored
in _______, and
doesn’t ___________.

14. → → ______________________________
= the ____________ of a harmful substance
____________as it passes to organisms at
_______________levels in food chain or web.
Plants pick up
DDT from water
& store it
Herbivores eat
plants and store some DDT
Carnivores eat
herbivores and store more DDT → →

16. American Bald Eagle was declared endangered in 1967. It has since been
The wide spread use of DDT threatened many species… especially fish eating birds like osprey, brown pelican, and
bald eagles.
DDT causes birds to lay
eggs with ___________
shells so eggs would
break when sat on.
American Bald Eagle was declared
endangered in It has since been
reclassified as _____________________

17. told of DDT’s harmful effects.
In 1962, American biologist _______________ published the book,_____________ which
told of DDT’s harmful effects.
The book led to a large public outcry and eventually resulted in DDT being _________ in the United States in the 1970’s
The book was one of the important events in the birth of the _________________________.

18. But . . . HAS HUGE IMPACT ON ECOSYSTEMS
Wearing away of topsoil = _________ is caused by plowing land and removing plant roots

19. But . . . HAS HUGE IMPACT ON ECOSYSTEMS
________ from feedlots and fields can contaminate surface and ground water
____________ happens to clear trees for beef farms
Raising cows uses lots of ______ and releases ________ into the atmosphere increasing climate change.

20. Impact of Agriculture
______________ = changing of fertile land in dry climates into desert areas caused by farming, overgrazing, and drought

21. But . . . HAS HUGE IMPACT ON ECOSYSTEMS
Many Midwest states rely
on the _________ aquifer
for their water needs.
We are using water faster than the ______cycle can replace it.
Evidence indicates this aquifer may _________ within years.

22. FRESH WATER RESOURCES Americans use BILLIONS of gallons of
freshwater daily for ________, ________
and ___________________
drinking
washing
watering crops

23. HOW DO WE HELP?
Modern_________ is changing how farmers farm and lessening the impact on the environment.
EX:
__________ imaging
_____ technology
enable farmers to
only apply chemicals
where__________

24. HOW DO WE FIX IT?
________ keeps plant residue in fields Reduces __________ and protects ecosystems from runoff

25. HOW DO WE FIX IT?
Planting legumes, alfalfa, grasses and other __________ keeps plants on soil between food crops reduces __________ and protects ecosystems from runoff
- reduces ______ - reduces need for fertilizer

26. HOW DO WE FIX IT?
______________ alternates what is crops are planted each year.
- helps control ________ without pesticides
- alternating with __________ replenishes soil nutrients without fertilizer

27. HOW DO WE FIX IT?
________________ = managing graze periods and herd densities
- improves nutrient cycling retains water ________ desertification

28. HOW DO WE FIX IT? __________ pest control
uses natural predators like insects or spiders to kill insects instead of chemical pesticides

29. HOW DO WE FIX IT?
_______________ = on hilly areas, plowing is done across the hill rather than straight up and down
- prevents soil _______ from runoff

30. HOW DO WE HELP ? Water conservation Protect wetlands and forests
Water treatment plants
Clean water regulations
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31. WAYS TO CONSERVE WATER

32. WHAT CAN YOU DO? - Eat _____ meat
- Don’t ______ food ~ 1/3 of all food produced worldwide, ($1 trillion) gets lost or wasted ~ US avg: 20 lbs/person/month wasted
Per capita/year
Food waste

33. WHAT CAN YOU DO? Be aware of ___________ water
Water the is used to produce products that we don’t know or don’t think about
The PRODUCTION OF:
1 kg wheat costs 1,300 L water
1 kg rice costs 3,400 L water
1 kg eggs costs 3,300 L water
1 kg beef costs 15,000 L water
1 cotton shirt costs 2,500 L water
1000 g of blue jeans costs 10,850 liters water
1 ton passenger car costs 400,000 liters of water
Building a house uses about 6 million liters of water
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