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.
Hide from trackers in the forest with a shallow trench dug in just minutes ... a last resort weapon when you've run out of bullets ... Here are several things you can do with an Army shovel and why modern day militaries that include Russian commandos train soldiers in the effective use of an "entrenching tool." How to Evade and Escape Tracking Dogs
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