First the link to this week’s complete list as HTML and as PDF.
Although the reaction itself is exothermic, ammonia synthesis through the Haber-Bosch-process consumes huge amounts of energy worldwide and the generation of its hydrogen feedstock even more so. Licht et al. have found a way to combine the two and use the enthalpy of the synthesis to partially offset that of splitting water. Contrary to steam reformation the process itself does not generate carbon dioxide as Service stresses, but as it uses electricity instead, that’s a meaningless gimmick to impress funding agencies.
Although Lemmen & Wirtz’s preprint is two years old already, it has still not appeared in print. While climate may have modulated the stops and jumps of Neolithic expansion, it can’t have been their main driver.