Transcript Unit 5- Climate Change

Climate Change
History
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Climate has changed and shifted for millions
of years
Earth goes through warming and cooling
phases
How do they know??
Data from ice cores, radioisotopes in rocks and
fossils, pollen, tree rings
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Gathered from drilling deep holes in
glaciers. Sites such as Antarctica and
Greenland.
Shows a year by year record
of trees growth. Can tell
weather patterns.
Greenhouse gases
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Include CO2, Methane, Nitrous oxide, CFC’s,
and HFC’s (Hydrofluorocarbons)
Fact – U.S. has 4.6% of the worlds pop. But
produces ¼ of world CO2 emissions
Reasons that back Global Warming
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The 20th century was the hottest in 1000 yrs
Since 1861, temp. of Troposphere has risen
.6Co
10 warmest years on record have occurred
since 1990
Glacial melting is increasing
Melting of permafrost in Alaska and Arctic
Sea levels have rose 4-8 inches in the last
century
Factors effecting global climate
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Oceans
Currents act like a conveyor belt. They store
CO2 and heat and is propelled by the wind.
An increase or decrease in temp. will lead to
a change in the currents direction.
Disruption or slowing of the belt would
cause drastic changes such as floods,
drought, severe storms, and heat.
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Outdoor pollutants
Aerosols
Produced by volcanoes and human activity
Can warm or cool the air depending on their
size and reflectivity
3. High levels of CO2
 This would actually increase plant growth
 Which would decrease CO2 levels
 But all of the CO2 would be returned to the
atmosphere when it dies
4. Increased Methane emissions
 A large release would come from permafrost
melting
 This would warm the earth, which would then
release more gas and so on.
Options
Three schools of thought
1.
Wait and see strategy
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U.S. currently holds this policy
2. Act now to reduce the risks from climate
change
3. Act now as part of a no-regrets strategy
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Prevention vs Cleanup
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Cut fossil fuels use
Shift from coal to natural
gas
Shift to renewable energy
Give this technology to
developing countries
Reduce deforestation
Limit urban sprawl
Slow population growth
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Scrub CO2 from emissions
Store CO2 by planting trees
Bury CO2 underground or
deep in the oceans
Repair leaky pipelines and
facilities
Use animal feed that
reduces emissions by
belching cows
Kyoto Protocol
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December 1997, 161 nations met in Kyoto
Japan to negotiate a treaty to help slow global
warming
Requires 39 developed countries to reduce
greenhouse emissions by 2012
Why the 39? – they are the major polluters
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This did not require developing countries to
lower their emissions until a later date
U.S. withdrew from participating in the
protocol in 2001
Why?
China and India were not under the regulations
Also, it was felt that it was too expensive
Why is this difficult to deal with?
1. The problem has many complex causes.
2. The problem is global.
3. The problem is a long term issue
4. The harmful and beneficial impacts of climate
change are not spread equally.
5. We cannot stop climate change, only slow and
adapt to it.
6. Phasing out fossil fuels may disrupt
economies and lifestyles.
Good Karma?
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Great Britain -reduced its emissions to its 1990
levels.
Mainly by improving energy efficiency in
homes and industry
China has reduced its CO2 emissions by 17%
Conversely, the United States CO2 emissions
rose by 14%
Seed Vault
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Svalbard Global Seed Vault, also known as the
doomsday Vault
Dug into a mountain side in the Norway
Will be used to hold large quantities of seeds
from plants throughout the world
Most importantly, seeds that make up most of
the agricultural industry.
No matter what, the seeds will be frozen