The second estimation in each paragraph is conditional on the first.
By 2020 some kind of CO2 emissions regulation (cap and trade) will be in place in the US(.85). But total CO2 emissions in the US for 2019 will be no less than 95% of total CO2 emissions for 2008 (.9).
Obama wins reelection (.7). The result will be widely attributed to an improving economy (in the media and in polls and whether or not the economy actually improves) (.85)
By 2020 open elections are held for the Iranian presidency (no significant factions excluded from participation) (.5). The president (or some other position selected through open elections) is the highest position in the Iranian state (.5)
How do you plan to judge #2? It seems rather subjective. (I mean, the economy is one of the factors attributed to every president winning or losing.)
I would like to propose this as a thread for people to write in their predictions for the next year and the next decade, when practical with probabilities attached. I'll probably make some in the comments.