I don't whole heartedly disagree with manipulating crops. People have been crossing and tweaking strains for many generations. While I recognize the need for a company to recoupe investment, plus a reasonable profit. If they do so in an all too aggresive manner or for a useless product, only they are the winners. I'm not a fan of companies roasting countries or communities over a pit, just because they don't add a penny to the shares.
While the above statement may seem harsh. I freely admitt there is no one simple answer. And none that wouldn't displace many tens of thousands, (probably more like many hundreds of thousands and more besides) I am forced to agree and for many years have thought the same way.
Once upon a time, the edges of some inhospitable places could support human life. But only on a sparsely populated basis. Yes, there have been great cities in the past, that thrived in such regions but only because they were on a major trade route. Those days in most cases are long gone.
Just because there is land and there are people, doesn't mean the two can coexist. Nor that either will flourish, just because a second bunch of people, only see the plight of another people. And are willing to ignore the needs of the land to maintain the notion, that mankind has ability and the right to conquer every square millimetre of this planet.
There is a finite amount of available land, (discounting land reclamation projects). There is however, an ever increasing human populous. The former cannot support the latter forever. And the latter cannot create the former in such quantity as would be beneficial to the whole. It's no good pretending we may have a problem in the future. We have a problem in the present.
There certainly have been associated cultural problems in enforcing such a law. But China was on the right lines I feel, when it introduced the one child law. As I say, it hasn't been without its problems but how much more trouble will there be, when humans are so numerous, that the planet is incapable of supporting that populous?