global warming consequences 1
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Global Warming Consequences 1. Credits go to the original owner.TRANSCRIPT
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`There is new and stronger evidence that most of the warming
observed overthe last 50 years is
attributable to human activity'
Intergovernmental Panel on Climate Change (United Nations), Third Assessment Report, 2001
`Most of the observed increase in globally
averaged temperatures since the mid-20th
century is very likely due to the observed
increase in anthropogenic
greenhouse gas concentrations.'
Intergovernmental Panel on Climate Change (United Nations), Fourth Assessment Report, 2007
`Warming of the climate system is unequivocal, as
is now evident from observations of increases in global average air and
ocean temperatures, widespread melting of
snow and ice, and rising global mean sea level.'
Intergovernmental Panel on Climate Change (United Nations), Fourth Assessment Report, 2007
Greenhouse Gases
• Let sunlight in– short wavelengths
• Earth heats up and radiates heat– longer wavelengths
• GHGs– don’t let Earth’s heat out
Increased Greenhouse Gases
Earth’s “cooling” system is “clogged”
• Net effect:– Earth warms to a
temperaturewhere itsradiation isshorter wave-lengths and canescape
Evidence from the Earth
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Global mean temperature
Global averagesea level
Northern hemispheresnow cover
Observations of recent climate change
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Global Instrumental Temperature Record
10 warmest years
1960 1970 1980 1990 2000310
320
340
360
370
380
Car
bon
Dio
xide
Con
cent
ratio
n (p
pmv)
2007
330
350
390
• Sea level rise• by thermal expansion AND ice melt
• Sea ice melting (Arctic and Antarctic)
• Glaciers melting worldwide
• Arctic and Antarctic Peninsula heating up fastest
• Melting on ice sheets is accelerating
• More severe weather (droughts, floods, storms, heat waves, hard freezes, etc.)
• Bottom line:• These changes do not fit the natural patterns unless we
add the effects of increased GHGs
Signs that global warming is underway
•Globe 1°F warmer than 100 yrs ago
•Last glacial max. was only 5°F cooler
•Not equally distributed– Some areas have warmed 11°F
– Winter and night increasing fastest(~5 times faster)
•Weather becoming more variable and more severe
Some climate change facts
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Arctic Sea Ice Melting
151980
-0.2
0.4
Ice
Ext
ent A
nom
aly
(106
km2 )
0.0
0.2
1985 1990 1995 2000 2005
-0.4
-0.8
-0.6
Arctic sea ice extent
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1941
2004
Melting of small glaciers and ice caps
17
McCarty Glacier, Alaska
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Kilimanjaro
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1970 2005
Kilimanjaro
20
1928 2004
Patagonia
Sea-level rise
Sea-level rise
• Fastest extinction rate in 65 M years (1000x normal rate)
• Increased disease (e.g. asthma, malaria)
• Increased poverty and hunger
• Sea level rise
• More extreme weather– Droughts
– Flooding
– Heat-waves
– Storms
Additional consequences
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Coral bleaching
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Mass extinction
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Habitat loss
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Palmer Drought Severity Index 1900-2002
What can you do?
Reduce consumption
Plant trees
Drive less
Shop smart
Alternative energy
Be informed
Unplug
Improve insulation
Don’t remain happy in ignorance