Answer: Industrial fixation of Nitrogen
Step-by-step explanation:
Industrial fixation of nitrogen has enabled humans to be able to make nitrogen fertilizers that are able to supply plants with much needed nitrogen that they need to survive. Indeed it is said that up to 40% of the nitrogen taken up by plants is from artificial sources.
The world's population might not be what it is today without this invention because it was able to return nitrogen to the soil at a time when humans needed it because we had been intensively farming land which led to it losing nutrients.
More nitrogen allowed us to keep farming and keep feeding the population which then exploded.