Climate Change II

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Climate Change II Guest Lecturer Jeff Chaumba,
Ph.D. student Geology
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• Monday Exam focused on water resources,
• Water pollution, coastal processes
  oceanography, glaciers, ice age and climate
  change
• Through this lecture (already on web)

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Indicators of Global Warming First three are
highly robust indicators
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Almost all alpine glaciers are retreating
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Sea level rising at a rate of about 12-14 cm/100
years (note it was Dropping before 1910)
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Arctic summer ice Minimum becoming smaller
Nat Geog
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Arctic summer ice Minimum Northwest Passage May
be feasible soon
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Today air temperature Appears to be rising 10
hottest years on record Are red
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Earths energy Balance interior Heat is trivial
compared To Suns input
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Electromagnetic Spectrum Note difference
between Visible light and infrared radiation
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Type of radiation a body Emits depends on Tsun
Emits shorter wavelenght Visible light, Earth
emits Infrared radiation
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Thus much of heat From sun radiated Back towards
space By the earth
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But greenhouse gases Trap the heatjust Like a
greenhouse does
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As in this example Where plants Adapted to
Warmer climates Grow in a Greenhouse on tundra
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Earths atmosphere CO2, CH4, O3, H2O are key
greenhouse gases
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Thus, Higher CO2 higher air temperatures

• -

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CO2 emissions by Region and per person Width of
bar is Proportional to Population Height of
bar is Proportional To amount emitted
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CO2 emissions by Region and per person US leads
in per person Carbon footprint
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fossil Fuel consumption not Only culprit. Note
land use contribution From S. Am. And Africa
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Land clearing more rapid oxidation of C in the
cleared forest plants CO2 increase in atmosphere
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Because of economic Growth, Future Chinese and
Indian Consumption a key issue for This century
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Projections Sea level Rise. Two scenarios
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Insect life cycles Adapt quicklymammals Not so
quickly In this case hatching Of flycatcher
infants Is later than optimum Because insects Are
adapting more quickly
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Sitka spruce die-off In Alaska due To beetle
infestation As a consequence Of warming
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Vegetation belts are Likely to shift
significantly
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Vegetation belts are Likely to shift
significantly Note expansion of arid Conditions
to the east In the southeastern US
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As is happening now in the Sahel Black lines
current rainfall Red lines 1931-1960 So arid
conditions moving south
Nat. Geog.
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Current Effects
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If all the ice Meltednot a Likely scenario