1. Global Climate Change Understanding the MIT study & what it means for public policy

2. MIT Study: 1- The Input Data Edward J. Garrity2 3 net Removal, outflow, = 3

3. MIT Study – 2, Hypothetical Future Edward J. Garrity3 Step 3 – Subjects asked to sketch the likely future CO 2 emissions given this scenario above.

4. MIT Study – 3, Example Results Edward J. Garrity4

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6. Why would smart people make this mistake? Cognitive processing System 1: Our brains operate automatically, quickly, little effort, involuntary reaction, intuitive, infers & invents causes & intentions, neglects ambiguity & suppresses doubt, is biased to believe & confirm, frames decisions narrowly System 2: deliberate, effortful, rational Edward J. Garrity6

7. System 1 at work We tend to use the information that is readily available (WYSIATI) System 1 is designed to jump to conclusions from little evidence; we construct stories from the evidence IF the story has coherence, then we have confidence in our opinions Edward J. Garrity7

8. MIT Experiment, CO 2 levels Problem was framed, presented in a simple manner: Atmospheric concentrations, what would future emissions look like? System 1 at work: Two variables are related, correlation heuristic If atmospheric CO 2 levels off, then emissions must level off to match results We easily ignore missing information Edward J. Garrity8

9. Heuristic Reasoning (System 1) In 2000, atmospheric CO 2 is 371 ppm In 2080, it reaches 400 ppm and remains level In 80 years it increases by about 8% By 2080, inflow (from industrial activity) would need to decrease by 50%! Edward J. Garrity9

10. Mental Model is Missing Bathtub analogy for stock & flow dynamics Atmospheric CO 2 Emissions, inflow removal, outflow Edward J. Garrity10

11. Stock & Flow Reasoning In order for Atmospheric CO2 levels to level off (equilibrium), … implies that inflows = outflows In 2000, inflow from human activity is 6 bil. Tons, but outflow (removal) is 3 bil. tons By 2080, inflow (from industrial activity) would need to be reduced to 3 bil. tons Therefore, need to decrease by 50%! Edward J. Garrity11

12. Implications Public does not understand the problem More needs to be done to halt Global Climate Change than people realize Although it is extremely difficult* to get, for example, a 20% decline in use of fossil fuels, … simply reducing by 20% means that we are still losing ground (Earth is heating). We need to get at least 50% reduction to keep stable Edward J. Garrity12