Not having had a television for several decades now, I hadn't thought much about the recent wave of survivalist shows (or their viewership). But, a couple of years ago, Ray Mears, the BBC television presenter of series such as World of Survival and Extreme Survival, came out here to the west coast of Vancouver Island to film episode six of his series Northern Wilderness. Mears roped in a few of my Nuu-chah-nulth friends to share with him their knowledge of food-gathering, and of the local materials that they harvest and use, such as cedar bark for weaving baskets and clothing.

While the resulting episode was interesting, it struck me as more of a cultural miscellany than any sort of genuine guide to survival. And to be fair on Mears, the Northern Wilderness series is not marketed as "how-to-survive" programming. But his earlier series such as Extreme Survival are. Searching past episodes on YouTube, I found all sorts of survival information in case I ever need to make a blowpipe or a squirrel trap, or find myself lost in the forest and in need of a log shelter (and happen to have a sharp sturdy axe and a pack of matches with me … honestly, on my wilderness trips, I am far more likely to carry a tent, or at least a tarp, than an axe). I have no doubt that Mears's skills and knowledge are genuine. However, I would label them as "bushcraft", which is a hobby, rather than "survival" skills.

I think a lot about survival – but not so much on my remote wilderness trips as when I am here at home. For really, how many of us will ever be in the situations that Mears, or the more extreme "survivalists", like Man v Wild Bear Grylls or Survivorman Les Stroud, contrive to find themselves: alone in the Costa Rican rainforest; or alone on a desolate peak in the Canadian Rockies?

No, the survival situation we are all more likely to find ourselves in is something more of a social disaster: food shortages resulting from climate change, fuel shortages leading to food shortages or epidemics such as flu or Sars – all of which threaten to cause significant social upheaval. And then there are natural disasters. For example, here where I live, the coming Cascadia earthquake and tsunami are likely to cause death and destruction to rival anything recently experienced in Chile or Japan. Who knows which of these disasters will hit first? Chances are that, within my lifetime (I'm counting on another 40 years or so), one or more will.

Personally, with my remote wilderness experience, I'd much rather be somewhere in the bush when they do. However, like the rest of you, I will most probably be here in town. Blowpipes and log shelters will not serve for much. Rather, our main challenge will be how, in such densely populated areas, to find enough food for ourselves and our families. And to continue to find that food for months ... or possibly years.

I have a garden. I have always had gardens, wherever I have lived. The act, or perhaps art, of growing food feels very natural to me. But lately, I have been impacted by the number of friends who come to see my famous veggie garden, but cannot even recognise the plants. They do not know where food comes from. A friend was shocked that radishes grow in the ground (he apparently thought they dangled from trees), and a girlfriend who decided to grow a tomato plant misunderstood my advice to remove the first spray of flowers; instead, she removed all of the flowers. I cannot comprehend where she thought the tomatoes were going to appear from. And then there's the universally baffled looks I receive when I point proudly to my asparagus patch. It is August, so the plants tower overhead. "But …" my visitors stutter, "where does the actual asparagus come from?"

Bear Grylls's Man v Wild series (known in the UK as Born Survivor) claims to have been the No 1 cable show in America, with a global audience of 1.2 billion. I cannot be sure whether these viewers regard it simply as entertainment, or whether they truly believe they are educating themselves. But Grylls himself believes he is imparting useful information: in a 2008 interview with David Letterman, he stated that the programme is "to show people what to do if everything has gone wrong, if you're in an extreme survival situation … what you can do to stay alive".

My garden may not be as glamorous, or as captivating on film, as the footage of Bear Grylls biting the head off a snake, skinning it and eating the flesh (not to mention what he did with it later that night). But when time comes, my ability to create a productive garden will be a key to my survival. Along with – if my neighbours have not similarly prepared – having the skills to defend it.

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