It's surprisingly difficult to grow food at the rate of 8.5 tonnes per hectare (Belgium) without petroleum-fueled water pumps, tractors, and harvesters, natural-gas based ammonia fertiliser, fossil-fuel-obtained potash and phosphate, fossil-fuel-based pesticides. Or water and arable land.
Take all that away and you're Zimbabwe, with 0.3 tonnes.
Humans already command or control some 25-40% of all primary plant production (NPP, or the photosynthetic ceiling), much of that made possible through modern mechanised architecture.
In the works already mentioned (Smil, Weissenbacher), the immense increases in ag productivity through such advances as assisted irrigation, mechanised plows, disks, seed drills, fertiliser, harvesters, etc., etc., are addressed in detail.
GDP, and economic prices generally, are exceptionally poor measures of net contribution and value. (Or of true real costs.)
Northwestern University economist Joel Mokyr, otherwise quite a technological optimist, discusses the failure of GDP to capture the true impacts of, say, antibiotics or vaccines. Their price-based contributions to GDP are de minimus, but their impacts on overall well-being are tremendous.
Take all that away and you're Zimbabwe, with 0.3 tonnes.
Humans already command or control some 25-40% of all primary plant production (NPP, or the photosynthetic ceiling), much of that made possible through modern mechanised architecture.
In the works already mentioned (Smil, Weissenbacher), the immense increases in ag productivity through such advances as assisted irrigation, mechanised plows, disks, seed drills, fertiliser, harvesters, etc., etc., are addressed in detail.
GDP, and economic prices generally, are exceptionally poor measures of net contribution and value. (Or of true real costs.)
Northwestern University economist Joel Mokyr, otherwise quite a technological optimist, discusses the failure of GDP to capture the true impacts of, say, antibiotics or vaccines. Their price-based contributions to GDP are de minimus, but their impacts on overall well-being are tremendous.
http://www.nationmaster.com/country-info/stats/Agriculture/C...