Transcript 6.4_Meeting_ecological_challenges

1 Review Why is the ozone layer important to living
things
Explain What are the major types of physical and
biological evidence for climate change
Propose a Solution Suggest one solution for the
fisheries problem. Your solution can be at the
international, national, regional, or individual level.
Explain how it would help, and what challenges you
see in implementing it.
2 Interdependence Refer back to the carbon cycle.
Describe how extensive burning of fossil fuels is
affection other reservoirs of carbon in the
atmosphere.
CH 6 HUMANS IN THE BIOSPHERE
6.4 Meeting Ecological Challenges
Ecological Footprint
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Total area of land and water needed both to
provide the resources and to absorb the wastes
Used to estimate the biosphere’s carrying capacity.
Footprint Limitations
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Calculating actual numbers for ecological
footprints is complicated
There is no universally accepted way to calculate
footprint size
Footprint in America is almost twice that in
England, more than twice that in Japan, and
almost six times that in China.
Ecological Footprint
North Atlantic Fisheries
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From 1950 to 1997, the annual world seafood
catch grew from 19 million tons to more than 90
million tons due to larger boats and fish finding
electronics
Recent dramatic declines in commercial fish
populations showed the fish supply is not an
endless.
North Atlantic Fisheries
Researching the Cause: Overfishing
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Gathered data including age structure and growth
rates
Analysis of these data showed that fish
populations were shrinking
Fish were being caught faster than they could be
replaced by reproduction.
Changing Behavior: Regulation of Fisheries
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U.S. National Marine Fisheries Service created
guidelines for commercial fishing
1996- Sustainable Fisheries Act closed certain
areas to fishing until stocks recover and others
seasonally to breed and spawn.
Changing Behavior: Regulation of Fisheries
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Aquaculture
 Farming
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of aquatic animals
Progress in restoring fish populations has been
slow
Regulations only apply to territorial waters.
Climate Change
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Global Warming
 Increase
in average temperature.
Physical Evidence: Changes in Sea Ice and
Changes in Sea Level
Biological Evidence
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Ranges (habitat) of organisms changing
Hibernation length is shorter.
Researching the Cause: Models and
Questions
How Much Change?
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Results of models predict the average global
temperatures will rise between 2°C to as much as
6.4°C by the end of the twenty-first century.
Changing Behavior: The Challenges Ahead
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Nations of the world have begun holding
international climate summits, at which they
attempt to work out agreements to protect the
atmosphere and climate.