  :I completely agree with the expansion tag. But it doesn't surprise me that there might be one optimal direction to go in, or that we can choose to go in that direction to a variable extent (i.e., by how many subsidies we transfer from fossil to renewable sources.)  The atmospheric greenhouse gas concentration (opacity in the blackbody infrared) governs the amount of money we will be spending on floods, so it should be possible to derive a dollar amount which needs to be transfered from fossil to renewable subsidies in order to minimize total financial losses.   