Earthquakes, tornadoes and hurricanes can cause you to leave your home or even be trapped there. Roads could be blocked due to fallen trees, power lines, or even damaged earth from the natural disaster. Rescue crews can not be in all places at once. You may have to wait it out for quite a while before its over. You won't be able to go to the store or to the corner market.
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.
Bob Kay, a nutritional scientist in Southern California, is prepping for environmental destruction due to massive earthquakes; politician Joshua Wander is preparing for a terrorist attack, teaching others about prepping and stocking up kosher foods (matzos and mre's); Ryan Croft is prepping for a global financial crisis by cultivating alternative food sources like spirulina and earthworms.
Doomsday Preppers has received varied reviews. Neil Genzlinger in The New York Times condemned it as an "absurd excess on display and at what an easy target the prepper worldview is for ridicule," noting, "how offensively anti-life these shows are, full of contempt for humankind." Nevertheless, "The program has been a ratings bonanza, with a 60-percent male audience, with an average age of 44." "Doomsday Preppers is the network's most-watched series". Brooklyn Bagwell, casting director for the second season, claimed it was the highest-rated show in the history of the National Geographic Channel.
If the fire is around you and you can’t escape, you don’t have many options, says Shane Hobel of the Mountain Scout Survival School. If there’s a pool or a pond nearby, jump in and try to wait it out there. Otherwise, if you have time, dig a trench that’s two to three feet deep and long enough for you to lie in. Soak a blanket in water, wrap it around yourself, and lie down in the trench. It’s risky, but at least you’ll have a chance.
There’s the compass. There’s the compass and map. And then there’s survival gear like this Garmin High Sensitivity GPS tool with its GLONASS receiver, 100K topographical maps, BirdsEye Satellite imagery subscription and triple axis compass. The screen is easily readable in the brightest sunlight or deepest night and the 8GB of memory mean you’ll always have the information you need now at your fingertips. If you’re serious about staying out of trouble when you venture into the unknown bring the Garmin High Sensitivity GPS tool with you and rest easy.