GCSE Geography - Climate Change - Unfinished

GCSE Geography - Climate Change - Unfinished

1. Evidence of climate change

   • 2005 - hottest year on record
   • In the last 100 years, Earth has warmed by 0.75℃
   • Oceans have absorbed 80% of the heat added to the climate
   • Since 1900, sea levels have risen globally by 17cm
     • Thermal expansion
       • As water warms, it expands
     • Land ice melting
       • Water released flows into the oceans

2. Effects of climate change

   • Case study: Great barrier reef
     • Threatened by ocean acidification
       • Caused by excess anthropogenic CO2
     • By 2100, ocean pH is predicted to fall
       • Falling from a current 8.2 to estimated 7.8
     • As CO2 is absorbed, it bonds with water, forming carbonic acid
     • Carbon is not available for marine animals to make calcium exoskeletons
       • This leaves exoskeletons weak and brittle and exposes animals to predation or destruction during storms
         • It affects the entire food chain and reef biodiversity
     • Extreme weather systems - e.g. floods and cyclones of 2010-11
     • Affects tourism, farming etc and so economy
     • Also threatened by pesticide runoff

3. Anthropogenic CO2 Production

   • 3/4 of the UK energy use comes from fossil fuels
     • Coal
     • Oil
     • Natural gas
   • The human race produces over 7 gigatonnes of CO2 every year
   • Logging and deforestation
     • Trees naturally absorb CO2 for use in respiration/photosynthesis
     • However, forests are being cut down