Famine, a lack of available food to a person, does not occur for the reasons that most people think it does. Most people think that famines occur because there is not enough food on earth to feed everyone. This is, much to their surprise, incorrect.
The world contains, as of last year, 6,602,224,175 people. Each of them will need, according to NASA, 3.1kg of food per day. If I do the math, this translates to 20,466,894,942.5kg/day. Quite a lot, certainally, but the planet is very large. 160,800,000,000kg of barley were grown last year. The amount of rice grown alone would feed everyone, albeit not well. (5.24 x 10^11kg of rice was grown in 2007).
However, food has a number of problems. It goes bad unless refrigerated. (Humans are not the only things on earth that eat! Rats, bacteria, and other pests do their best to eat up any food they get their paws, pseudopods, or grasping impliments on.) It gets stolen. Farmers expect to be paid for their efforts, as farming is hard work. Some of it is worth more as fuel, or alcohol. (I'm looking at YOU, corn.)
Every starving person on earth is arguably starving for political reasons. The most obvious is poverty -- They are unable to provide the farmer with an economic exchange due to a lack of funds. This can be dealt with in a way that imposes few political problems. Namely, a third party charitably buys food for them. This way, the people eat, the farmer gets paid, and everyone is happy, except for the hard core libertarians.
More insideously, however, are dictatorships that force people to live in places that do not have food, forbid them from leaving, and forbid trade outside of their country. And most insideous of all are dictatorships that have decided by fiat that certain people do not get to eat as a way of exterminating them forever. Our resident historian notes that no democracy has ever had a famine, as people tend to leave areas where food is hard to come by.
As an engineer, there's no machine I can build to overthrow cruel dictatorships. There's no chemical reaction for justice. Starve happy dictatorships have to be dealt with diplomatically, politically, or possibly militarily if the first two options don't work. Or possibly another solution is at hand. Ask your local political science expert.