Throughout most of human history getting enough to eat has been a serious problem. The Green Revolution changed this for many humans. The Junk Revolution also changed things, especially in the United States: now we have significant numbers of people who are both obese and malnourished. There is currently talk of Blue Revolution in which aquaculture (farming fish, mollusks and so on) changes things on a large scale. Whatever the color of the next revolution, food will be an ever increasing matter of concern.
One point of significant concern is that modern agriculture tends towards monoculture. That is, factory farms will typically grow vast amounts of a single species of plant (or animal). While this does allow for efficiency and uniformity, there are some serious problems with this approach, as shown by the infamous Great Famine of Ireland. By relying heavily on a very small number of crop species we are very vulnerable to the impact of crop pests, diseases, and so on. While the use of pesticides and other means have helped, this is obviously a losing battle-we are simply contributing to the selection of the pests and diseases that can withstand our attacks. It is, obviously enough, simply a matter of time before we will not be able to keep up. The obvious solution is to move away from monoculture to having more diverse crops. While this will change the nature of factory farming, it will make us less vulnerable to pests and diseases. It will also provide people with greater variety in their food choices.
Another point of concern is that our agricultural methods rely heavily on chemicals. Modern crops are drenched in pesticides, herbicides and fertilizer. In many cases this is overdone, thus wasting money and also adding more chemicals to the environment than necessary. There is also the obvious concern that these chemicals are having a significant impact on the environment and our bodies. Changing our approach to a less chemical intensive one will save money and also reduce the impact on the environment.
A third point of concern is the rapidly growing population in general and the growing number of affluent people. More people means, obviously enough, more food consumption. Having more affluent (relatively speaking) people generally means an increased demand for “luxury” foods like meat and seafood.
Since the earth is finite and limited in resources, there is obviously a point at which the earth simply cannot support the dietary needs of the human population. While technology will expand this carrying capacity, this is also not limitless. Making matters worse is the fact that growing meat and seafood is far more resource intensive that raising plant crops. While the exact numbers vary, creating a pound of farmed meat can take up to 16 pounds of plant feed. In any case, animals convert plant food to meat inefficiently, so growing plants to feed meat animals is a very inefficient way of feeding the human population.
However, humans tend to really like meat and there is a strong psychological link between wealth and the consumption of meat (some also link eating meat with being “manly” or “macho” while vegetarianism is often seen as being for “sissies”). As such, as the world’s middle class begins to grow, they will demand even more meat. Unfortunately, the world probably does not have the capacity to produce enough meat for the expanding middle classes (at the very least, the planet could not provide enough for everyone on earth to eat like the average American) which could lead to some problems.
Given the finite resources and growing populations (especially populations that will demand meat and seafood) it seems reasonable to consider that the future will see a return to conflicts over croplands and growing space. Hitler claimed he was looking for “elbow room” for his people and we might see new wars fought for “hamburger room.” This is, obviously enough, not inevitable. Technological and social changes might head off the problem or their might be a die back of the human population from other causes.