VIENNA, Austria

--The past couple of years have seen a flood of books and articles foretelling the end of life as we know it once the ancient Mayan calendar runs its course on Dec. 21. It's anyone's guess why we should take this particular prediction any more seriously than dozens of previously failed apocalyptic musings. Of course, more than 99 percent of all species that have inhabited the planet are now extinct, so our day will almost certainly arrive. But this extinction process has been under way for more than 4 billion years. So, it takes a very big gulp to swallow the idea that a humanity-destroying event of the sort that sent the dinosaurs packing 65 million years ago is just a few weeks away.

Nevertheless, there is a germ of truth hidden in the snowstorm of Mayan-calendar-based warnings. Today, humankind faces a variety of challenges heretofore unprecedented in the history of our species. Failure to meet these global problems could indeed throw a big monkey wrench into our post-industrial way of life, if not our continued existence as one of the dominant species on the planet. The global "might happen" catastrophes run the gamut from threats sent our way by nature, solar flares that would short out our electronic gadgetry and climatic events like global warming that may flood most major cities and shrink agricultural production to starvation levels in many parts of the world.

Then there are the even more interesting demons of our own design, such as a global pandemic, a nuclear holocaust and/or a failure of the electrical power grid, any one of which could easily crash our current lifestyles just as effectively as anything "Mother Nature" might throw our way.

Since, for the most part, there is little we can do about a super volcano or a killer asteroid other than try to prepare to survive it, let me focus here on the human-caused variety of extreme events, what I like to call "X-events," and consider how these game-changers occur and how we might prepare to deal with them.

THE COMPLEXITY GAP