Storage

There are a number of reasons why to consider the long term storage of food.

Climate change is bringing variability into food prices. An example is the price of bananas post hurricane Yasi in Australia. Prices went from $2 per kg to $14 per kg within a very short time frame. Naturally people will change their buying preference away from bananas to a substitute product. However, there are more and more of these extreme variations, with less and less choice. As the environment becomes more hostile, it makes sense to store food when there is a surplus.

There will be more extreme events that leave your household isolated. These could be as a result of flooding, fires, riots, heat events or storms.

This is not only about food, but also water.

The main techniques for long term storage or food are salting, drying and bottling. Obviously the existing information for these techniques is extensive and I would suggest referring to Wikipedia for the different methods according to food types.

Plans need to be made for water storage for both heat events and drinking. Long term water storage is going to require low tech purification. There are references online for various techniques depending on your situation.

What I will focus on is events I can foresee and possible methods to cope. I would appreciate any input.

Extreme events

One factor that has been hypothesized for the loss of Scott's party to the South Pole was the lack of effective calorie allocations.

From here.
The number of calories burned at rest is called the basal metabolic rate, and it’s a measure of how much energy your body uses just to keep all of your complex bodily functions up and running and in check (i.e. your body temperature regulated, your heart beating, your brain humming, and so on).

How many Calories do I Burn doing Nothing? 
Here’s the formula to find your resting metabolic rate:

For Women: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)
For Men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in years)


There are various threats depending on where in the world you are. I am going to try and cover a few.

Disease

During an outbreak of disease the best option is to stay put. Depending on the circumstances authorities will contain it, but there is a period of extreme risk. Some parts of the world, and depending on the degree of migration, containment may be difficult. An example might be Southern Europe and the influx of illegal immigrants and the threat that poses with Ebola.

A store of food and water is going to be vital to holding out.

Nuclear winter

Cold war is over, so the nuclear threat is gone? Nuclear pollution is why you should still care.

Is it reasonable to assume that one would be able to stay in a restful state for months on end? During a nuclear winter scenario, there simply may be no choice.

The following images are from some soviet work to determine the effects of a nuclear winter.

The estimated time frame would be 1 - 2 years, but that is dependent on models that have never been tested. In addition, the models were done without consideration to climate change. Finally, the models failed in estimating the impact from fires during the Kuwait war. So, basically nobody knows.

Being totally sedentary for an extended period of time would create other health problems. However, using metabolic reducing techniques discussed elsewhere would result in lower calorie requirements.

Anyway you look at it, it is a significant amount of food to store.