For global catastrophic risks the costs of food storage become impractical for most of the population  and for some such catastrophes conventional agriculture would not function due to the loss of a large fraction of sunlight (e.g. during nuclear winter or a supervolcano). In such situations, alternative food is necessary, which is converting natural gas and wood fiber to human edible food.
Civilians such as forestry workers, surveyors, or bush pilots, who work in remote locations or in regions with extreme climate conditions may also be equipped with survival kits. Disaster supplies are also kept on hand by those who live in areas prone to earthquakes or other natural disasters. For the average citizen to practice disaster preparedness, some towns will have survival stores to keep survival supplies in stock.
This group has a primary concern with maintaining some form of legal system and social cohesion after a breakdown in the technical infrastructure of society. They are interested in works like The Postman by David Brin, Lewis Dartnell's The Knowledge: How to Rebuild Our World from Scratch, or Marcus B. Hatfield's The American Common Law: The Customary Law of the American Nation.
Wetfire is a non-toxic product that won’t produce clouds of noxious smoke. All it takes is a tiny bit sprinkled on the camp stove to get it going even when the rain or snow is coming down in blankets. In survival situations many perish because they’re unable to create the warmth they need to counteract cold, wet conditions. Wetfire is pocket-sized survival gear that allows you to withstand nature’s worst. Wetfire has a 5 year shelf life and can be activated using any stormproof lighter or other sparking device.
To me, the best option is to store emergency food. How much? If you have none, store enough for a few days. If you have enough for a few days, get enough for a week. How much you store depends on what time frame you think you're at risk for having to be completely independent. The early settlers of the southwest liked to store enough food for a whole year and still do to this day!