Comment by unearth3d

Pop. needs to fall back to ~1.7B as that's Earth's human natural carrying cap. - as determined by the pre-Haber Process natural Nitrogen pool. Vaclav Smil, SciAm, July 1997, 76–81. More relevant than ever. Synth. N is not a solution as is isotopically diff. and harms plant cell structure in our food.