|"There's No Tomorrow", Seq.4 - FOOD
Script, References & Further Reading.
The global food supply relies heavily on fossil fuels. Before WW1, all agriculture was Organic. Following the invention of fossil fuel derived fertilisers and pesticides there were massive improvements in food production, allowing for increases in human population.The use of artificial fertilisers has fed far more people than would have been possible with organic agriculture alone. 
Fossil fuels are needed for farming equipment, transportation, refrigeration, packaging - in plastic,  and cooking.
Modern agriculture uses land to turn fossil fuels into food - and food into people.  About 7 calories of fossil-fuel energy are used to produce 1 calorie of food.  In America, food travels approximately 1,500 miles from farm to customer. 
Besides fossil fuel decline, there are several threats to the current system of food production: Cheap energy, improved technology and subsidies have allowed massive fish catches. Global fish catches peaked in the late nineteen eighties,  forcing fishermen to move into deep waters.  Nitrogen run off by fossil fuel based fertilisers poisons rivers and seas, creating enormous dead zones.  At this rate, all fish populations are projected to collapse by 2048. 
Acid rain from cities and industries leeches the soil of vital nutrients, such as potassium, calcium, and magnesium.
Another threat is a lack of water. Many farms use water pumped from underground aquifers for irrigation. The aquifers need thousands of years to fill up, but can be pumped dry in a few decades, like oil wells.  America's massive Ogallala aquifer has fallen so low that many farmers have had to return to less productive dry-land farming. 
Additionally, The use of irrigation and fertilisers can lead to salinisation: the accumulation of salt in the soil. This is a major cause of desertification. 
Still another threat is topsoil loss. 200 years ago, there were 6 feet of topsoil on the American prairies. Today, through tillage and poor practices, approximately half is gone. 
Irrigation encourages the growth of stem rust fungi like UG-99 - which has the potential to destroy 80% of the world's grain harvest. According to Norman Borlaug, father of the Green Revolution, stem rust "has immense potential for social and human destruction."
The use of biofuels means that less land will be available for food production. 
An area has a finite carrying capacity. This is the number of animals or people that can live there indefinitely. If a species overshoots the carrying capacity of that area, it will die back until the population returns to its natural limits. 
The world has avoided this die-off by finding new lands to cultivate, or by increasing production, which has been possible largely thanks to oil.
To continue growth, more resources are required than the Earth can provide, but no new planets are available. In the face of all these challenges, global food production must double by 2050 to feed the growing world population. 
1 billion people are already malnourished or starving.  There will be challenges in feeding over 9 billion in the years to come, when world oil and natural gas production will be in decline. 
REFERENCES & EXTRA READING
 Green Revolution Food Production:
 Fossil Fuel Inputs to Food Supply:
haber-bosch effect on world population
 Between 7 and 10 Calories of Fossil Fuel to Produce 1 Calorie of Food:
getting fossil fuels to my plate.
 1,500 Miles From Farm to Plate:
video with michael pollan about food miles
 Peak Fish:
 Deep Sea Fishing:
year of peak fish harvest?
 Nitrogen Runoff, Hypoxia:
 Fish Collapse:
estimated global fish landings 1950–1999
nature cover story - only 10% of all large fish are left in global ocean
the sixth extinction
 Aquifer Depletion:
 Ogallala Aquifer:
ogallala aquifer map and information
the ogallala aquifer depletion
 Soil Salinization and Desertification:
 Topsoil & Soil Erosion:
humans causing erosion comparable to world's largest rivers and glaciers
the relative efficacy of fluvial and glacial erosion over modern to orogenic timescales
land degradation maps of senegal
global assessment of human-induced soil degradation
global soil degradation
 Ethanol vs. Food:
exxonmobil 2004 report (PDF)
 Carrying Capacity:
 Food Production and 2050:
water requirements for food production to 2050
feeding the world in 2050 - an optimistic view
 Axioms of Overshoot: