L. David Roper
http://www.roperld.com/personal/RoperLDavid.htm
2 July, 2016
Ammonia is used to provide nitrogen for crop fertilizers. It is made from natural gas and nitrogen gas taken from the air:
Data for world ammonia production are available at http://minerals.usgs.gov/minerals/pubs/commodity/nitrogen/:
The curve is a 2-Verhulst-functions fit to the data.
Because of the close correspondence with ammonia production and natural-gas extraction ammonia production should closely follow natural-gas extraction. Here is a graph in which ammonia production and natural-gas extraction are arranged to be close together:
The ammonia production data starting at 1995 can be fit to the natural-gas extraction data with a linear function:
The function is 6.23365 + 1.116576 x (natural-gas extraction).