The world had no artificial fertilizer before World War II; manure and other "natural" fertilizers did a poor job. Agriculture was just creeping and could not support food growing for the world. Britain had a near famine in the early 1900s as wheat production was minuscule and they had to import about 80% of their wheat.
During World War I, the Allies blockaded Germany's ports and prevented access to nitrates (from saltpeter in Chile) and -- they thought -- the manufacture of explosives by Germany would come to a dead stop. But, mysteriously, explosive manufacturing actually increased in Germany during the war. After the war, Germany tried to keep this process a secret from the Allies, but a German chemist divulged everything.
The German "secret" was discovered in 1909 by a Fritz Haber ... and is known as the Haber Process. By 1913 -- just in time for the start of WWI--- the high pressure and high-temperature equipment was on line to manufacture ammonia with this process. They derived the necessary hydrogen from natural gas or other hydrocarbons and the nitrogen from the air. After the war, the Haber process was adapted to make ammonia for fertilizers. The result was a vast increase in agriculture and the basic reduction of world hunger.
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Now here's the catch: Most hydrogen is derived economically from one of the hydrocarbons fossil fuel (natural gas, etc). Elimination of fossil fuels would mean reliance on electricity (obtained from intermittent wind and solar) to use the electrolysis process to make hydrogen from water. There would be much less fertilizer in the world, and much less food production. By 2050, when the world's population reaches 10 billion, mass starvation will result.
So, AOC, maybe you should consult a scientist instead of a politician before implementing your Green New Deal plan -- unless you have a secret source for hydrogen so we can make ammonia when the wind doesn't blow and the sun doesn't shine But, cheer up, maybe Musk will have his Star Ship ready for a Mars trip soon. I think I'll get an early ticket.