Axial Tilt - Earth System Science Education Alliance

porcupineideaBiotechnology

Dec 16, 2012 (5 years and 22 days ago)

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Amber Jimenez, Jeremiah Hinton, Linet Madeja, Marco
Messah, Mytet Gumin

Dr.
Witiw

Group #3


Colder winters in
Europe and North
America



Average global
temperatures were
about 2
-
3 degrees
Fahrenheit cooler



No agreement on
beginning date of

Little Ice Age



Medieval Warming
Period

1.
Background

2.
Causes

1.
Sunspots

2.
Milankovitch cycles

3.
Volcanic activity

4.
Thermohaline

3.
Impacts

1.
Agriculture

2.
People

3.
Economy

4.
Environment

5.
Art & Literature

4.
South American Little Ice Age & Ice Vikings

5.
Recommendation

1.
World food supply


THEN VS. NOW

2.
Projections based on trends



Dark regions that appear on the surface of the
sun


It is dark because the temperature is cooler than
its surroundings (3,700 degrees C vs. 5,500
degrees C)


Not really dark…



Low Sun Spot count during the Little Ice Age


Low Sun Spots means less heat coming from the
sun, leads to a cooler earth



Eccentricity


Shape of earth’s orbit around the sun


Axial Tilt


The inclination of the earth’s axis in
relation to the plane of orbit around the
sun


Precession


The changes in the orbital ellipse causes
changes in the solstices



More Elliptical would mean extreme
weathers between seasons


Less Elliptical means a change in
seasons (much like ours currently)


The tilt determines
which area of the earth
receives the most
amount or the least
amount of sunlight


The position of the earth on its
elliptical path around the sun


This changes when and how long
the seasons last

Definition:


The global ocean
circulation that
is driven by
geographic
differences in
the density of
sea water, which
are controlled
by temperature
(thermal) and
salinity (
haline
)

Warm, salty
water from the
Tropics gets
carried
through to the
North Atlantic

Once there, it
begins to cool,
releasing heat
to the
atmosphere &
warming the
North Atlantic

The water
becomes
cooler, more
dense & sinks
to the deep
ocean

Once in the deep
ocean, water flows
south through the
ocean basins, is driven
up by wind driven up
near the
Antartic

and
rejoins near surface
currents to begin the
process again.

Past changes in
thermohaline

circulation have
occurred during
periods of relatively
rapid climate change,
such as transitions in
and out of glaciations,
like the Little Ice Age

Ocean Conveyor Belt


Discussion that
meltwater

floods reduced the salinity
and density of the surface
ocean in the North Atlantic,
causing a reduction in the
ocean's
thermohaline

circulation and climate
changes around the world


Eventually, as the
meltwater

flux subsided, the
thermohaline

circulation
strengthened again and
climate recovered

Meltwater

floods
reduced salinity &
density of the
surface of the
ocean

Continental
Ice Sheets
Melting

Freshwater
added to the
North
Atlantic


Mount Pinatubo 1991

-
Sent fine ash and gases high
into the stratosphere

-
Aerosol Effect, reflects
incoming solar heat back into
space, increasing the earth's
reflective power (
albedos
)

-
Higher
albedos

coincide with
lower temperatures


Tambora

1815


-
produced so much gases and
particles that it lowered
earth's temperature enough
that it robbed Europe of a
summer the following year


High Volcanic
Activity
during Little
Ice Age
demonstrate a
lowering

of
temperatures,
cooling off the
climate.


Increased prices
on wheat and rye


Peaks in prices due
largely because of
poor harvest


Fusarium nivale


Parasite


Devasted crops



Animals had nothing to eat
causing a huge decline in
livestock



Led to famine and dearth



Famine: a severe shortage of food
resulting in starvation and death



Dearth: an insufficient quantity or
number




Dearth, famine, and poor nutrition killed millions of
people


Vikings in Greenland; Iceland


St. Anthony's Fire Illness


Convulsions, hallucinations, gangrenous

rotting of the extremities, and even death


Malaria


Mala aria


‘bad air’



Became very hostile


Cattle raids, men enlisted into war etc.


Witchcraft/ Witch hunts


Scapegoats to blame for their suffering


Fertile fishing grounds of Newfoundland Banks were thought to
have been found by fisherman in the late 1400's



movement of colder waters from the north



English fisherman benefited by the southern movement of
herring off of Norway.



Increase in deep
-
sea fishing helped to build the marine
population and strength of the country



The failure of crops in Norway


growth of merchant shipping.


Coastal farmers whose crops failed turned to selling their timber
and to constructing ships in order to transport the timbers
themselves.


Increased grain prices


Lower wine production


Farmsteads destroyed


less
tax revenues collected due to
decreased value of the
properties


Cod fishing decreased


Scottish fisherman


Sudden end to mining
operations


Hohe Tauern mountains
of the Austrian Alps





High frequency of
storms


Large hailstorms


Sand storms due to
severe erosion and
high winds


Sea flooding


Reshaping of coastal
land regions



Writers and artists were influenced by the
climate change


Explorers over the centuries have noted changes to the
San Rafael Glacier in South America


Antonio De Vea, Hans Steffan Hoffman, the a BBC
report’s data correspond with timeline of the LIA


The retreat and advance


of the San Rafael Glacier


corresponds with the


conditions proposed by


the LIA


The
Anglo
-
Saxon Chronicle

famously notes the
first appearance of Viking raiders on the shores
of Lindisfarne in AD 793


Tax reports indicate that the population of
Iceland fell from about 77,500 in 1095, to around
38,000 in the 1780's



Asia plants more than
50% of the developing
world’s wheat crop

Asia produces &
consumes 90%
rice grown

50% of the
developing
world’s Maize is
produced in Asia,
some
Eastern/Southern
African parts too

Now

Investment in world food
security, to food safety
and food quality, and to
sustainability, ensuring
they remain available to
the public at large

Investment in Irrigation
Systems throughout
Africa, Latin America


Considerations

-
The availability of varieties of
seed with tolerances for
extremes of cold or heat,
wetness or drought

-
Development of a greater
variety of crops that focus on
virus resistance, quality and
tolerance to
abiotic

stresses.

Developing countries should be
invested in (Latin American,
African) to increase crop
representation and
enhancement of crop traits

Total area
cultivated with
GMO crops stands
at about 44.2
million hectares,
up from 11 million
hectares just three
years ago.

About 75% of this area is
in industrialized
countries. Substantial
plantings largely
concern four crops:
soybean, maize, cotton
and canola.

About 16% of the
total area planted
to these crops is
now under GM
varieties, and two
traits
-

insect
resistance and
herbicide
tolerance
-

dominate.


Danger that the scale of
the investment may lead
to selective
concentration on species


“Hard" intellectual
property rights over
seeds & planting
material, the tools of
genetic engineering.


Patents on crops


LIA in South America:

Historical records of San Rafael glacier advances (North Patagonian Icefield): another clue to 'Little
Ice Age‘ timing in southern Chile?. A. Araneda, F. Torrejon, M. Aguayo, L. Torres, F. Cruces, M.
Cisternas, and R. Urrutia (2007) The Holocene 17, 987
-
998

http://news.bbc.co.uk/2/hi/science/nature/3662975.stm

http://www1.lanic.utexas.edu/project/etext/llilas/vrp/villalba.html



LIA in Greenland/Vikings

http://www2.sunysuffolk.edu/mandias/lia/decline_of_vikings_iceland.html

Lamb, H.H., 1995, Climate, History and the Modern World, Methuen, London.


the end

questions?