Mao’s famine was caused by killing birds, because he did not listen to science.
You're missing about 10 other bad decisions in there, and you'll never guess what those 10 decisions were related to.
Millions of… millions of cattle killed.
Again. If we killed all the animals right now in every country in the world we would have....
More food.
Animals eat food. They provide less than they eat, so if you took all the food that would have gone towards cattle and instead put them towards humans, you'd see people eating more, not less.
I'm not totally going to say that that wasn't a factor, but at the end of the day the famine in the Soviet Union still had a root cause.