Arguably the most important (if least well known) industrial advancement of the 20th century, the Haber-Bosch ammonia synthesis process essentially conquered food scarcity by creating the means to mass produce fertilizer — fertilizer then used to fortify food harvests around the world.
But the production of ammonia — the building block for ammonium nitrate fertilizer — generates a problematic byproduct down the line: carbon dioxide. Lots of it: more than two tons of carbon for every ton of fertilizer. It accounts for an estimated 1.4% of global carbon dioxide emissions. So, while the process countered mass starvation, it also began