Headlined ''The burning issue: native gardens a killer on our doorstep'', you will still find it preserved on this paper's dashing, pathbreaking website (just type ''Joan Webster'' into the search window) if you missed it last Saturday.

Although I am a native plants zealot and usually find myself quite cranky and humourless with people who don't share my zeal, Webster's is a stimulating, pugnacious, thought-manufacturing piece and deserves some serious consideration.

Please read it all for yourself, but here is how it begins.

''Tigers are native to India. Do Indians keep tigers in their gardens? Or allow them to roam the streets? No. They could kill someone. So why do we Australians feel a compulsion to surround our houses with native plants; grow them in suburban streets? They can kill people. This is the key to the tragedies that devastate Australia every summer; the killer, highly flammable, native vegetation that we encourage close to our homes … It is arguably the main reason Canberra suburbs burned in 2003 …'' and more, much more in the same highly readable vein.

My mind remains ajar on all of this (although, entertaining as it is, the tigers/native foliage analogy is as ill-fitting as the comparison of a cannibal with a turnip). But one first reaction is that Webster vastly overrates how many native gardens there were in Canberra in 2003 and how many there are now.

She makes the Canberra homes of 2003 and of today sound swarmed-around and swarmed-over by natives when in fact those of us who keep an eye out for such things know that the all-native or even part-native garden is an unusual thing in Canberra.

As gardeners, we Australians are still overwhelmingly natives-averse and are still growing the gladdie-infested, rose-festooned gardens of the Old World that we hark from. There is only one almost-all-natives plant nursery in Canberra, while every other retail nursery's natives section is a tiny, unfashionable corner offering a fraction of what the nursery has for sale.

Native gardens are oddities still, and for example, in my own long and winding and tiresomely typical suburban Canberra street mine is the only front garden of the kind (infested with native horticultural man-eaters) that Webster imagines is the Canberra norm. But I swear my mind is ajar, held open, stopped from slamming shut, by a big pot of (native of course) kangaroo paws.

The fact that Webster's man-eatingly alarming story has given us something to worry about allows me to foxtrot neatly into my next subject, the edge.org 2013 question of the year.

This year Edge has asked 155 people with very good minds to ask themselves What Should We Be Worried About?

Every year the Edge resulting collection of answers/ideas (previous questions tackled have included What Is Your Dangerous Idea? What Are You Optimistic About? and What Have You Changed Your Mind About, And Why?) seems the most stimulating English-language reading to be had from anywhere in the world. Your columnist commends it to each of this column's seven or eight thinking readers.

Things worried about by 2013's 155 worriers include psychology professor David Buss's alarm that men and women no longer have enough other men and women to mate with and that this is leading to an epidemic of sexual treachery.

Psychology professor Douglas T. Kenrick fears that idiots are about to take over the world and make it into an idiocracy run by numbskulls.

Historian of ideas Noga Arikha worries about ''collective amnesia'' by which she means ''the stunning historical blankness students from the world over display when they arrive at college'' not having the foggiest idea of anything that happened before 1992.

Seth Shostak, senior astronomer of the SETI Institute, says we should lose sleep over the possibility of an attack by ''malevolent, extraterrestrial beings''.

Science writer Matt Ridley shares this columnist's worries about the rise of superstition, agonising that ''superstition can help bring down whole civilisations'' and that ''the fundamentalists are breeding at a faster rate than the moderates within all the main religious sects''. Other worriers are concerned about the world's alarming underpopulation and about the shocking possibility that, in our shameful ignorance and lack of imagination we may never invent a better form of government than democracy.

I mention all this because what's so refreshing about the essays of the Magnificent 155 is that their worries are, mostly, very big worries.

I commend them as role models for those Canberrans who waste their Letters to the Editor on their teeny-weeny, First World, bourgeois NIMBY worries. What if Summernats makes some noise? What if a new floodlight pylon alters the view we've grown used to? What if we have to pay for plastic shopping bags? What if arrogant cyclists stray, outrageously into our driving lanes? What if the government leaves the grass unmown and untidy?

Here, at edge.org, entertainingly discussed, are the sorts of worries that really matter, worries about the whole planet, our whole species, about the wider world beyond our suburbs and our narcissistic suburban selves.