We already had a sufficient global crop failure in 2010: Drought in USA, fires in Russia. Russia stopped export. Global grain prices skyrocketed. Result: The Arab Spring. (The average Egyptian spends a major part of income on bread. They need to import a lot, given their overpopulation, but no longer have enough oil to export to finance bread price subventions.)
I actually think (but have no proof resp. sufficient knowledge) that such large scale consistent crop failures will get less probable in the future: 2010 the jet stream got stuck over USA and Russia. I expect the jet stream to get more chaotic, if not dissolve, at least during summer. So, less of these blocking patterns.
Anyhow, some hunger doesn't hurt. How will they ever learn? You can't overpopulate arid regions like Egypt or Yemen forever. I would of course prefer to starve the Mullahs and old Pope Ratzinger. They are guilty of incitement to suigenocide.
Another destabilizing factor is industrial agriculture itself. As it depletes soil organic carbon, it is selfdestructive long-term even without climate change. The agriculture of the future is small-scale diversified family farm agriculture, together with some networking and subventions and insurance against crop failure. This can not only provide enough food for 8bn people but also jobs, plus carbon sequestration, water retention and other ecosystem services.
Forget rocket science, study the soil cosmos below your feet.
Short video excerpts from longer ones by John D Liu:https://youtu.be/8f8Yqgj-TXg
First thing everybody can do: Don't eat beef.