Good point 'Barde.
If we're going to look at crop yields, we have to get really back to basics;
- Define how the nuclear exchange occurred in your campaign. (Intensity, tempo and coverage)
- Define what climate changes result from the exchanges.
- Define the local effects of those climate changes.
For instance, a Nuclear Autumn means you're not going to get good grains. A localised devastation of forestry can change the micro-climate (this happened in the middle of the state where I live, the trees were cut down for pasturage resulting in an increase in aridity. The entire area is now drought-prone in the nation's wettest state) and bring drought to formerly wet areas.
It also gives the Gm the excuse to have weird weather effects
