Interesting!
Fritz Haber & Robert Le Rossignol (who are both out of the running for being killed by their own inventions) might have a reasonable competing claim to their shares in "most impact on the atmosphere" for: https://en.wikipedia.org/wiki/Haber_process
> Due to its dramatic impact on the human ability to grow food, the Haber process served as the "detonator of the population explosion", enabling the global population to increase from 1.6 billion in 1900 to 7.7 billion by November 2018. [...] Nearly 50% of the nitrogen found in human tissues originated from the Haber-Bosch process.
Being responsible for removing a bottleneck that enabled +100% more biomass of tool-using fossil-fuel-burning* primates arguably may have been a much larger indirect impact on the atmosphere (and many other things, for better or worse), leaving aside the direct impact on the nitrogen cycle.
* also, for various subsets of primates, perhaps add: airplane-flying, meat-eating, truck-driving, aircon-running, tree-planting, fish-catching, land-clearing, television-watching, hackernews-reading, list-enumerating, ...