This is a very practical nuts-and-bolts "How to save the economic world". Macro institutions are neccessary to avoid various prisoner dilemma decision issues.
The UN, World Bank, IMF and a few others attempt to carry this mantle, and they do not really execute, and for the same reason - national interest always overides collective interests.
With regards to environmental issues, Shiller's proposals in this text would be quite good at addressing the current conflicts that exist in formulating an agreement.
In the end, however, the best voting and pricing machine is the market. If we price carbon in the marketplace and limit its release, market prices will reflect all known information about carbon.