Food production in the westThe bad News
Our current food producing systems are built on a constant supply of cheap oil, oil is used to make our fertilisers pesticides and herbicides, power our machines on the farm and to transport our food around New Zealand and around the world. The fertilisers are particularly dependant on oil and without these fertilisers most of the current food producing regions will be left useless. This use of oil to grow food means that we are putting tens or hundreds of times more energy into growing our food than we are getting out of it. Without oil we would have to use human or animal labour so we would have to get out as much or more energy from our food than we put in.
The huge amount of cheap energy that fossil fuels have unlocked have allowed humans to be taken out of the equation when it comes to food production. Evidence of this is shown by the dissapearance of the small farm and the proportion of the labour force directly involved in food production which is now only a small percentage of the population.
Internationally the main threats to agriculture as we know it are
Depletion of underground aquifers which provide water for irrigation such as in canterbry.
Peak oil or other disruptions to our oil supply which would significantly limit our ability to produce food.
Ongoing climate change which would change rainfall patterns and frost patterns.
Erosion and salinisation.
Centralised food production and distribution systems which are highly fragile and unable to deal with disruption.
Any persistant disruption in a major cereal producing region such as Australia, America or the rice producing regions of Asia would significantly raise food prices internationally. Combine several of these disruptions and you would have a situation where much of the world would be unable to get food at a reasonable price.
The truly terrifying fact behind these disruptions is that no matter what happens we will be unable to produce food as we currently do soon because virtually all our food producing land is being eroded or is suffering from salination. Our entire food production system will not last beyond the end of cheap fuels and even if these last indefinetly the land we grow on land will be so degraded food production will be impossible on the levels needed to sustain our population.