I think the original comment about political statements costing trillions are when say the government subsidizes corn ethanol.

There is good consensus that corn ethanol is energy negative, and that it doesn't result in cleaner air or less greenhouse gases due to production costs.

This mis-allocation of capital hinders development of truly better alternatives, and sets back innovation. These setbacks, beyond the cost of the subsidy and the lack of improvement in the areas targeted, do cost trillions.