But oil production is not the whole story. Nutrients like nitrogen and phosphorus were also required for the “Green Revolution”.
Nitrogen is present in large quantity in the atmosphere (78% of its composition). The Haber-Bosch process for obtaining nitrogen uses one percent of all energy consumed by humans [5]. Nitrogen can also be fixed in the soil using micro-organisms such as rhizobium and azotobacters. If there is sufficient energy, nitrogen will be available.
Phosphorus may be the real bottleneck of agriculture. [6]
Population growth was only possible because we found phosphorus deposits and cheap energy to extract, transform and transport it to farms. When we plot data of world population versus world phosphate production, we find a significant correlation.