I remember taking this big test in Chadron Nebraska and there were over a hundred high schools. I represented my school in biology and they asked an essay question. Describe the green revolution. I was clueless then and I probably gave an incorrect response but I have since learned what it was. It was biology, not agricultural science. Anyway.
noun: green revolution; plural noun: green revolutions
a large increase in crop production in developing countries achieved by the use of fertilizers, pesticides, and high-yield crop varieties.
Humans are very good at improving crops. Corn used to be the size of your little finger. Soy beans were originally grown for oil and now they are a major source of protein. Wheat has changed dramatically from it's wild ancestors. All Hass Avocados are clones from a tree no more than 10 miles from where I write this. I suspect that CO2 helps but the other reasons I provided probably help more.