Climate Change

• Evidence for Climate Change- Ice Cores

  Ice sheets have a new layer every year

  ---> gases trapped in each layer allow temperature to be recorded
• Evidence for Climate Change- Temp records

  Thermometers accurately record temperature since 1850

  Historical records are less reliable

  An increase of 0.85 degree Celsius sine the end of the 19th century
• Evidence for Climate Change- Shrinking glaciers and melting ice

  Glaciers shrinking = temperatures rising

  2014 - Arctic sea ice thinning by 65% since 1975
• Natural Causes of Climate Change- Orbital changes 


  Affects how much solar radiation the earth receives - more energy , more warming

  • Eccentricity - earths orbit changes from circular ( interglacial ) to elliptical ( glacial ) every 100000 years
  • Obliquity - every 41000 years earth's axis goes between 22.5 - 24.5
• Natural Causes of Climate Change- Solar Activity

  There are changes in solar energy output = sunspots are marked

  ---> reduced solar output means the earths climate may become cooler in some areas
• Natural Causes of Climate Change- Volcanic Activity

  Eruptions emits gas and ash into the atmosphere

  ---> Ash blocks out sun reducing temperatures

  Sulphur dioxide converts into sulphuric acid acting like a mirror , reflecting sun rays
• Human Causes of Climate Change

  Fossil fuels - burning them releases carbon dioxide

  Deforestation - when cut down , carbon dioxide is released

  Cattle farming - increase in western diets , emits methane ( 24x more effective in trapping solar radiation )
• Impact of Climate Change

  Sea levels could rise , covering low lying areas and affect 80 million people

  Droughts and floods are more likely as extreme weather increases

  Increased demand for water in summer , puts pressure on water supplies

  Tropical storms will increase in magnitude ( strength )
• Mitigation of Climate Change- Alternative energy sources

  The burning of fossil fuels contribute to 87% of human made carbon dioxide emissions ( deforestation= 9% industry= 4% )

  Can be reduced through renewable energy , can last to the future
• Mitigation of Climate Change- Carbon Capture

  Coal is the most polluting of fossil fuels - China gets 80% of its electricity from it

  Carbon capture and storage ( CCS ) uses technology to capture carbon dioxide . When captured , carbon gas is compressed , transported to an injection well , then injected in the ground to be stored
• Mitigation of Climate Change- Planting Trees

  Trees are carbon sinks and remove carbon dioxide from the atmosphere
• Adapting to Climate Change- Coping with rising sea levels 


  Flood warning systems put in place and flood barriers being built

  Houses with built stilts
• Adapting to Climate Change- Changing agricultural systems 


  Plant new crop types to suit new climate conditions

  Biotechnology to create new crop varieties

  ---> resistant to extreme weather
• Adapting to Climate Change- Managing Water Supply 


  Water meters for excessive water use

  Rain water and waste water collected and recycled