T2 Climate and Change

Topic Two

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Volcano Carbon Footprint

Examples
Mount Etna, Italy : 1 million tonnes CO2
Mount Pinatubo, Philappines (1991) : 42 million tonnes CO2

All volcanos in a typical year produce 300 million tonnes of CO2
   > humans still produce twice as much as this

Volcanos emit 130-230 million tonnes of CO2

They create a warming effect (long term) and a cooling effect (short term) 

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Natural Causes of Climate Change

Eruption Theory (short term)
- Kraktoa (1815) : Global temps' decreased by 3 degrees celcius due to ash
- Toba (73 000 years ago) : iceage - population of 40 people
Ash and gas rise to the stratosphere by high winds; like a blanket from the sunlight. The light reflects of the ash and back into space, which is cooling

Sunspot Theory (mid term)
Sun's output isn't constant; detected cycles show an increase/decrease in solar energy.
Sunspot activity: uneven temps' develop on the sun's surface that are small black dots in photos. These come and go in irregular cycles lasting 11 years.
More spots = greater temperature, the sun is working harder.

Orbital Theory (long term)
Changing orbit can be circular or elliptical. The axis tilt upright or side ways and wobbles: the alters the amount and area sunlight is recieved. Could start/end an iceage! known as Milankovitch cycles.

Asteroid Collisions (short term)
large asteroid colliding with earth = cooling (poss. e.g. dinosaur extinction 65 million years ago)
cloud of dust is thrown up by impact, blocking the sunlight 

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Warm/Cold Periods

100 million years ago (dinosaur time), conditions were hotter
 Pleistocene was the last iceage which started 1.8 million years ago, ended 10 000 years ago 
 Holocene is the last 10 000 years (the warmer period)

Interglacials (warm periods) - last for 10-15 000 years
Glacials (cold periods) - last for 80-100 000 years

20 000 years ago, these countries, now ice-free were covered by ice sheets 400-3000 metres thick;  UK, Canada, North America, Iceland, Sweden, Norway, Denmark, Finland, Germany, Poland, Northern Russia, Latvia, Lithuania and Greenland 

Medieval Warm Period... 
Began: 800
Ended: 1400
Lasted: 600 years

Little Ice Age...
Began: 1540
Ended: 1830
Lasted: 290 years

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Techniques to Understand Climate History

Geological:
1) Ice Cores
How it works: a frozen record contains layers of ice, with the oldest at the bottom, youngest at the top. Layers contain air bubbles containing CO2. Change in air content = temp change.
Reliability: figures show CO2 + temp relationship in averages
2) Fossil Records
How it works: shows animals/plants who prefer warm/cool periods, when they were alive + thriving. UK shows arctic mammal fossils; we must have once been colder.
Reliability: less so; hard to find fossils, fossil record is incomplete, no statistics

Historical:
1) Regular Events: Migration, harvest and blossom. If earlier = warmer/ later = cooler
Reliability: vague, no exact temps/times
2) Photo/Drawings: Weather is throughout the year/in different years
Reliability: biased, artistic licence, exaggeration, no data 
3) Written Records: Diaries/books/newspapers (show weather records) - colder then
Reliability: newspapers more than books, may have figures
4) Tree-rings (dendrochronology): trees are sensitive to change in temp/sunlight/precipitation
Cold = thinner rings due to lack of new growth
Reliability: most; unchangeable, but some photosynthesise at different rates 

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The Vikings

Medieval interglacial period led the Vikings to travel to Greenland and utilise the climate for resources (population of 3/4000)

How They Destroyed the Environment:
 1) overexploited farmland, soil became infertile
 2) soil erosion - due to charcoal production and deforestation for fuel
 3) built churches, a monastry, nunnery and a cathedral
 4) didn't adapt/learn from the locals
 5) they were vulnerable; dependent on trade from other countries

How They Could Have Benefitted from Inuits:
- Caught seals when food was scarce
- Dressed suitably for warmth 

Little Ice Age Facts : - ice sheet reached as far as London
                                 - Amsterdam, Berlin and London were ice-covered
                                 - woolley mmmoth bones are found in the mid-north sea
                                 - sea levels were 100m lower then

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1315 Little Iceage

Impacts of the Little Iceage on the Europeans
1) Cold/rainy spring and summer; different seasons
2) Wheat and oats didnt ripen; harvest failed
3) Long term change
4) 1317 'Great Famine' hit and lasted until 1325
5) 10-20% of farmers died of hunger; couldnt grow/sell/buy 

How Europeans Adapted to the Cold
- learned to farm crops that could survive in the cold
- made most of frozen rivers; held fairs which encouraged buyers
- abandoned high hill side farms

Impacts of the Little Iceage
farming; lack of crops
colder temperatures lead to longer winters
rural and poorer people affected most
1300s presented riots against the King for help 

Explaination... -  Sunspot Activity: much lower than today
                      -  Volcanic Activity: coincides with active period of volcanic activity

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Megafauna

Can survive in cold climates - large animal = smaller surface area to volume ratio
   - reduces heatloss by small features
   - fluffy and blubbery for insulation
   - large paws: balance/spread weight
   - carnivorous; adapted to hunt, eating meat gains more heat and energy
During the pleistocene age, megafauna lived in Europe and North America - after a few centuries of melting, all 135 species were extinct.

Due to...
Natural causes: - unable to adapt to new conditions, weather/plant life changing food chains, some                           places left drier, scarcity of food 
Human causes: - humans migrated and hunted megafauna

Megafauna Today: tigers, pandas, elephants, rhinos, polarbears
- all endangered (human cause)
- temp. is rising, 1/4 of species cannot survive the future worst predictions
- 30 000 species become extinct per year 

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The Atmosphere

21% Oxygen
78% Nitrogen
<1% Carbon Dioxide, Methane, Water Vapour

Greenhouse effect is natural and has always existed; without it the world would be 30 degrees cooler in a permanent iceage where we couldn't survive.
The enhanced greenhouse effect is causing issues, greenhouse gases make the planet 16 degrees warmer, 'comfortably warm'. CO2 regulates the temperature. Enhanced = extra layer 

 Greenhouse Gas                        Human Contribution                    % Increase since 1850

 Carbon Dioxide                            Burning fossil fuels +                               +30%
                                                          deforestation
 

 Methane                                    Gas pipeline leaks, farming                         +250%
                                                           rice + cattle

 Nitrous Oxide                           Jet engines, cars, fertilisers +                        +16%
                                                          sewage farms

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Air Masses

The UK Temp Maritime in July is 17 degrees and January is 5 degrees. We have 4 season due to the constant rainfall; affected by the Gulf Stream (a warm ocean current keeping us warmer)
Air Masses = huge body of air with uniform temperature and humidity, which bring weather                                associated with where the air is from

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Weather and Warming

The Jet Stream creates a polar front where warm and hot air masses meet.
Due to the Earth's spin and wind directions, the polar front will shift. The UK gets 700mm-2500mm of rain due to 3 maritime air masses. Warm, moist air from the Atlantic is blown onto land, forcing clouds to rain = frontal rain

low pressure = depressions; wet weather
high pressure = anticyclones; dry weather 

It's hard to predict temp's due to global warming because...
- Earth is unpredictable
- no evidence/comparisons to form predictions
- other temp. increasing factors (e.g. volcanos, sunspots)
- we dont know if our energy sources may change
- changing lifestyles (e.g. more recycling? less transport?) 

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Climate in Different Countries and Predictions

China + India's Carbon Emissions Increased; Developing
- increase in population
- industrialising
- export + trade 
UK + Germany's Decreased; MEDC's
- educated
- take action; signed treaty and must pay fine if overproducing
- new technologies (e.g. electric cars) 
African Countries produce small amounts; LEDC's
- cant afford cars/holidays
- not accesible due to level of industry
- little technology; live traditional lifestyles

Projections:
Temp: Evidence - 19/20 warmest years recorded since 1980
                         - risen by 0.75 degrees between 1905 and 2005
Future predictions; best: rise of 1.1 degrees by 2100 / worst: rise of 6.4 degrees by 2100
Sea levels: Evidence - melting ice sheets
                                 - levels rising 3mm a year since 1993
Future predicitions; best: rise of 30cm by 2100 / worst: rise of 1.2m by 2100 

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Climate Change LEDC's

Bangladesh, Asia

Why is this area vulnerable?
Soc/Eco: - income of over £1 a day                   Env/Phys: - 2/3 live less than 5m above sea
               - 7th most populated (150million)                       - frequent floods
               - few are educated                                            - subsiding ground
               - dependent on agriculture                                 - glaciers in Himalayas are melting

Impacts of climate change?
Soc/Eco: - school flooded 8 times                     Env/Phys: - fewer fish
               - rivers wash out communities                            - eratic weather 
               - trapped in povery                                             - inundated fields - lost homes/land
               - water born disease                                            and infertile soil
               - rich leave for jobs
               - changing diets
               - no clean water 

What help do they get?
flood shelters on high land, rafts to travel/high walkways, raised house levels, charities (UK gave £75 million), farmers are educated, high tier in house protects valubles. 

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