I know that you specified Human Made Climate Change, but I'll get this out of the way: The largest driver of climate, the earths temperatures,and changes to the climate is Solar Activity.
This does not take away a responsibility for a more sustainable agricultural model.
The population of the earth is growing, not shrinking. Barring a large depopulation that means that supporting this population means large scale agriculture - You could go with more non animal nutrition but it is less "nutrient dense", and would take more cultivated acres, more petro chemical fertilizer, etc. Which means more fertilizer run off, higher potential of chemicals getting into the aquafiers(sp) etc.