Climate change - not as complicated as you might think

Climate change - not as complicated as you might think

Presented at Nerd Nite Melbourne, April 2014. See video recording here: https://www.youtube.com/watch?v=3qVp97VQQSs

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Damien Irving

April 01, 2014
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Transcript

  1. Not as complicated as you might think… Damien Irving PhD

    candidate University of Melbourne
  2. Climate change… ž  What is it? ž  How do we

    know it’s happening? ž  How do we know it’s our fault? ž  What will the future climate look like? ž  Why aren’t we doing anything about it? ž  As individuals, what can we do about it?
  3. What is it? The Greenhouse Effect

  4. What is it? Problem: Greenhouse gas concentrations are on the

    rise…
  5. What is it? Consequences of trapping extra energy…

  6. What is it? Surface temperature is only one of many

    indicators…
  7. How do we know it’s happening?

  8. How do we know it’s our fault? ž  How  do

     we  know  that  we  put  that  excess   carbon  dioxide  in  the  atmosphere?   —  Historical  records  of  human  ac8vity     —  Lighter  isotopic  composi8on  of  atmospheric  carbon     —  Decrease  in  atmospheric  oxygen  (combus8on)   ž  How  do  we  know  the  excess  carbon  dioxide   has  caused  the  rise  in  global  temperature?   —  Our  knowledge  of  the  Greenhouse  effect   —  Our  knowledge  of  the  Earth’s  climate  history   —  Nothing  else  makes  sense   —  Climate  modelling  
  9. How do we know it’s our fault? Climate model simulations:

    with (pink) & without (blue) humans
  10. What will the future climate look like? ž  Easy  projec8ons

     (high  confidence)   —  Temperature   —  Sea  level   —  Ocean  acidity   ž  More  difficult  projec8ons  (lower  confidence)   —  Rainfall   ◦  Storms,  tropical  cyclones  etc  
  11. What will the future climate look like? Projected changes in

    rainfall
  12. Why aren’t we doing anything about it? ž  We can

    emit 565 more gigatones of CO2 to stay below 2°C warming ž  Fossil fuel companies have 2,795 gigatons in their reserves
  13. As individuals, what can we do about it? Westpac divestment,

    8 March 2014
  14. ž  What is climate change? —  The trapping of extra

    energy from the sun ž  How do we know it’s happening? —  We measured it ž  How do we know it’s our fault? —  Some cool scientific detective work ◦  Basic concepts from the 1800s, lighter carbon, decreasing oxygen, computer climate models, historical records, … Conclusions
  15. Conclusions ž  What will the future climate look like? — 

    Hotter, higher seas, more acidic oceans —  Wet get wetter, dry get drier ž  Why aren’t we doing anything about it? —  Money / vested interests ž  As individuals, what can we do about it? —  Don’t be an individual - get involved in the community/movement ◦  e.g. divestment, rallies