Climate and Change

Climate and Change

1. Climate and Weather

   • Climate is average weather conditions
   • Weather is day to day changes
     • e.g. temperature

2. Looking at the past

   • Distant past
     • Know about climate change...
       • From fossilised...
         • Animals
         • Plant
         • Pollen
       • From U shaped valleys left
         • By retreating glaciers
       • Sample ice sheets
         • From Antarctica
   • Recent Past
     • Know from...
       • Old photos
       • Painting
       • Journals/diaries
       • Recorded harvest dates

3. Causes of Climate Change

   • Eruption Theory
     • Huge eruptions releasing
       • Ash
       • Sulphur dioxide
     • Cause a blanket of ash and gas
       • Blocking sunlight reaching the earth's surface
         • This cools down temperatures
   • Asteroid Collisions
     • When really large asteroids hit
       • It sends tonnes of ash and dust into the the atmosphere
         • It would block sunlight
   • Sunspot Theory
     • Sunspots are black areas on the sun
       • Not permanent
       • more spots means more solar energy
       • Less means less solar energy towards earth
         • Meaning colder earth
   • Orbital Theory
     • The way the earth orbits the sun changes the temperature
     • Sometimes the orbit is more circular
       • and sometimes it is more ellipse
     • The earths axis tilts
       • Sometimes straight
       • Sometimes tilted
     • Sometimes the earths axis wobble
     • It changes how much sunlight the earth recieves

4. Viking Greenland

   • Erik the Red
     • Banished to Greenland
   • Beginning of the medieval warm period
   • There was land and sea free of ice
     • This meant
       • They could farm
       • Have good trade links
       • They could hunt
   • After 4 centauries
     • The little ice age began
       • It was colder
         • Meaning
           • Less food
           • More sea ice
             • So no trading
     • The Vikings in Greenland Died out

5. Little ice age

   • started in 1315
   • Colder and wetter summers
   • Caused fammine
     • Because of failed harvests
     • Potato began to be grown
   • Glaciers grew
     • Destroyed villages and farmland

6. Megafauna

   • Mass extinction
     • Humans
       • hunted megafauna
     • Migrated
       • Due to warmer climate
       • To find climates that suited
         • Food would have been hard in new location
           • disrupting food chains
   • big animals
     • over 40kg
     • e.g. mammoth

7. Greenhouse Effect

   • Gases in the atmosphere trapping heat from sun
     • let heat in but little out
   • Natural process
     • keeps temperature
   • greenhouse gases
     • CO2
     • Methane
   • short wave solar radiation
     • passes through atmosphere
       • short wave radiation is reflected off earth's surface
         • some long wave is reflected back into space
         • is reflected back to earths surface

8. Enhanced Greenhouse Effect

   • Lots more greenhouse gases produced by humans
     • mostly CO2
     • Warmer Earth
       • melting ice caps etc...
   • e.g.
     • burning fossil fuels
     • transport
     • Homes
     • industry
   • New ways to slow production of greenhouse gases down
     • renewable energy

9. UK

   • Climate
     • temperate maritime
       • mild temperatures
       • rain all year
     • Affected by air msses
       • Polar front
         • it moves
           • ffects whether or not be have cold or warm whether
       • Polar and arctic air from north
       • tropical air from south
   • Changing
     • Warmer?
       • Polar front pushed north
       • South rather than north
       • warm air holds more moisture
         • more rain?
       • positvies
         • lower heating costs
         • more UK tourism
         • Fewer elderly deaths from cold
         • more exotic crops
       • negatives
         • Droughts and water shortages
         • air conditioning costs
         • plants and animals might die out
         • more illness
           • .g. heat stroke
     • Colder?
       • polar front could move south
         • heavier rain?
           • more flooding?
     • Wilder?
       • More storms
       • more flooding
       • more heatwaves
       • Hard to predict

10. Egypt

    • Developing country
      • low emissions
    • feel large impacts of climate change
      • temp rise of 8 degrees by 2080
      • desertification
      • less rain
        • failing crops
      • desertification
      • heatwaves
        • 99% of people
          • live on 5%of the land
    • Nile important for Water
    • if sea levels rise by 50cm
      • 1/3 of Alexandria will be under water