Firstly, where do you plan to evacuate a significant percentage of the world's population to ? Secondly, how are you going to decide who is worthy of evacuation and who has just put his gun down and is hiding with the locals to make sure he can carry on the abuse and oppression in their new location ? Finally, how are you going to get this food to them ?
Food nutrition or availability isn't the problem - the problem is identifying valid recipients and then getting it past every government agent, checkpoint thug and warlord into the region.
I've worked in strange places in Africa and I've seen a lot of this first hand. The only fix is for people to organise and setup governments that are fair and have their people's interests at heart. That won't happen without massive amounts of education and people believing they can change things, and vested external interests stepping aside so that this can happen. I doubt very much that this will happen in my lifetime, short of a massively powerful nation deciding it is in their best interests.
Watching China's march into Africa is very interesting to me for these reasons.