I think it will be a Genetic Famine.
Some European company tested a genetically modified crop in India that failed horribly, forcing thousands of farmers into poverty (many of them committing suicide). Not only did the crop fail, but it left no re-plantable seed.
Imagine another 50 years, and all our agriculture is based on genetically modified crops. Then 1 year, something happens to make all crops in the world fail.
It would cause a panic/riots for organic food, massive inflation - the economy will completely collapse. Lesser countries will starve to death and start war.