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Geography - Climate Change - Coggle Diagram
Geography - Climate Change
Climate Change
any significant change in the weather of a region over a period of at least several decades
Evidence
Quaternary Period
most recent geological time period
2.6 million years ago - present
before
warmer and stable
during
global temp shifted between cold glacial periods (100,000 yrs)
warmer interglacial periods (10,000 yrs)
last glacial period ended 15,000,000 yrs ago
since then, climate warming
Global Warming
sharp rise in global temp over last century
Ice and Sediment Cores
ice sheets
layers of ice
one ;layer formed each year
scientists drill to get long cores
analysing gases trapped
tell the temp
remains of organisms found in cores taken from ocean sediments
Temperature Records
since 1850s
global temp have been measured with thermometers
reliable short-term record
Historical records
newspaper weather reports
extend record
Pollen Analysis
preserved in sediment
identify date
show which species were living
conditions that plants live in now
preserved pollen from similar plant show similar conditions
Tree Rings
new ring each year
thicker in warm / wet conditions
cores and count rings to find age
thickness = climate
10,000 years
Causes
Natural
Milankovitch Cycles
small changes in the way Earth moves around sun (1,000s yrs)
Orbital Changes
solar radiation Earth recieves
more energy = more warming
Variations
Stretch
circular to elliptical
Tilt
axis at angle
Wobble
axis wobbles like spinning top
caused glacial & interglacial cycles
Volcanic Activity
eject large quantities of material
some particles reflect rays back to space
Earth cools
Mt Pinatubo
short-term
Human
Fossil Fuels
CO2 released
coal, oil, gas
Farming
livestock
methane
rice paddies
flooded fields emit methane
Deforestation
plants remove CO2
trees are cut
stop taking in CO2
CO2 released
trees burnt as fuel / agriculture
Effects
Environment
glaciers shrink
ice sheets melt
rising sea-levels
low-lying and coastal areas
flood
sea ice shrinking
loss of polar habitats
declining species
coral reefs
bleaching
changing precipitation patterns
distribution and quantity of species
high latitudes
damaged or destroyed habitats
extinct
People
deaths = hot increased
deaths = cold decreased
areas hot or dry
inhabitable
low-lying coastal areas lost
flood
migration and overcrowding
political tensions
farming
crops suffered
lower crop yields
malnutrition
ill health
extreme weather
more ££ spent on predicting, reducing, rebuilding